1. Nick break
2. Side bend
3. Charpy impact
4. Face bend test

Q1a. With reference to the previous question and the correct answer, what type of test is this?

1. Qualitative
2. Tentative
3. Quantitative
4. Sensitive

Answer – Q1: b. Side bend & Q1a: a Qualitative

Explanation: The Side bend test reveals the sidewall fusion issues upon bending, making it the best option. Why other other options are not correct or less correct?

• Nick break: This test is carried out for butt weld and the sample is notched so that the fracture path will be in the central region of the weld. We can detect internal defects like lack of fusion, solid inclusions and porosity that are visible on the fracture surfaces but for lack of sidewall fusion this would not be an appropriate test because the fracture is done on the centre of the weld.
• Charpy impact: This test measures the toughness of the weld by striking a notched specimen, but it does not directly show fusion defects.

• Face bend: This test bends the weld from the face of the weld, but it is less effective in detecting sidewall fusion issues compared to the side bend test.

Explanation for Question 1a:

Destructive tests can be divided into two groups, these are:

• Quantitative tests: Measure a mechanical property (Numerical data)
• Qualitative tests: Assess the joint quality

Let us analyse each options:

• Qualitative: The side bend test is qualitative because it visually assesses the weld’s integrity by bending the specimen and observing any defects like cracks or separations. Hence, this is the most appropriate option.
• Tentative: This term does not apply to the nature of the test.
• Quantitative: This term refers to tests that measure numerical data, which is not the case for the side bend test.
• Sensitive: This term does not describe the type of test.

Q2. Which of the following is a planar imperfection?

1. Lack of sidewall fusion
2. Slag inclusion
3. Linear porosity
4. Root concavity

Q2a. With reference to the previous question and the correct answer, how could this defect be caused?

1. Amperage to high
2. Voltage too high
3. Amperage too low
4. Gas flow rate too low

Answer – Q2: 1. Lack of sidewall fusion, Q2a: 3. Amperage too low

Explanations: Welding discontinuities are categorized into two main types based on their dimensional characteristics:

• Volumetric Discontinuities: These are three-dimensional defects that have length, width, and thickness. Examples include slag inclusions and porosity.
• Planar Discontinuities: These are two-dimensional defects that lie on a single plane. Examples include lack of fusion and cracks. Hence, option 1 i.e. Lack of sidewall fusion is the correct answer.

Explanation for Q2a:

• Amperage too high: High amperage can cause excessive penetration or burn-through, but it is not typically associated with lack of fusion
• Voltage too high: High voltage can lead to a wider, flatter bead, but it does not directly cause lack of fusion
• Amperage too low: Low amperage can result in insufficient heat input, leading to poor fusion between the weld metal and the base material, causing lack of sidewall fusion. Hence, this is the correct answer.
• Gas flow rate too low: Low gas flow rate can cause porosity due to inadequate shielding, but it does not directly cause lack of fusion

Q3. A fillet weld has an actual throat thickness of 8mm and a leg length of 7mm, what is the excess weld metal?

1. 2.1 mm
2. 3.1 mm
3. 1.8 mm
4. 1.4 mm

Q3a. With reference to the previous question and the correct answer, if this excess weld metal was removed the fillet would be a?

1. Concave fillet weld
2. Convex fillet weld
3. Undersized fillet weld
4. Mitre

Answer – Q3: 2. 3.1 mm & Q3a: 4. Mitre

Explanations: 

• The theoretical throat thickness for a fillet weld is calculated as (Z X 0.7) = 7×0.7=4.9 mm
• The excess weld metal is the difference between the actual throat thickness and the theoretical throat thickness: 8−4.9=3.1 mm.

Explanation for Question 3a

• A convex fillet weld has a curved outward face.
• A concave fillet weld has a curved inward face.
• A mitre fillet weld has a flat face. Hence when the excess weld metal will be remover the weld profile will become similar to mitre fillet weld.

Q4. BS EN 17637 allows the use of a magnifying glass for visual inspection, but recommends that the magnification is:

1. x2
2. x2 to x5
3. x5 to x10
4. Not greater than x20

Q4a. With reference to the previous question, what likely defect will this help to find?

1. Excess weld metal height
2. Root concavity
3. Internal lack of fusion
4. Undercut

Answer – Q4: 2. x2 to x5 & Q4a: 4 Undercut

Explanations: X 2 to x5: This range is recommended by BS EN 17637 for visual inspection as it provides sufficient magnification to detect finer surface defects

Explanation of Question 4a: Undercut: This defect, which appears as a groove along the weld toe, can be more easily detected with magnification in the range of X 2 to x5. Hence, it is the most appropriate answer. Let us analyse other options:

• Excess weld metal height: This defect is usually visible to the naked eye and does not require magnification.
• Internal lack of fusion: This defect is internal and cannot be detected by visual inspection with a magnifying glass.
• Root concavity: This defect is typically visible without magnification.

Q5. Pipe bores of some materials must be purged with argon before and during TIG welding to:

1. Prevent linear porosity
2. Prevent burn-through
3. Prevent oxidation of the root bead
4. Eliminate moisture pick-up in the root bead

Q5a. With reference to the previous question and the correct answer, what material would this pipe be?

1. All materials
2. Aluminium and stainless steel
3. Stainless steel
4. Carbon steel and stainless steel

Answer – Q5: 3. Prevent oxidation of the root bead & Q5a: 2. Aluminium and stainless steel

Explanations: Let us understand, why purging is required on rood bead from the back side?

Root bead is first pass, vulnerable to air inside pipe. Oxidation weakens weld, reduces corrosion resistance. Since, Argon is inert gas. It displaces oxygen and prevents reaction with hot metal i.e oxidation. Hence, correct option is Prevent oxidation of the root bead (option no.3)

Why Other Options are Less Correct:

(1) Prevent Linear Porosity: Argon helps, but oxidation prevention is primary.

(2) Prevent Burn-Through: Shielding indirectly affects heat, but purging isn’t burn-through control.

(4) Eliminate Moisture: Argon reduces moisture, but oxidation prevention is main goal. “Eliminate” is too strong.

Explanation for question Q5a:

Correct: (2) Aluminium and stainless steel

Reason: These metals are highly reactive with oxygen at welding temperatures.

Essential: Purging is critical to prevent oxide formation, ensuring weld quality & corrosion resistance.

Why Other Options are Less Correct:

(a) All materials: Purging beneficial for many, but essential for reactive metals like Al & SS.

(c) Stainless steel: Correct, but incomplete. Aluminium also critically needs purging.

(d) Carbon steel & Stainless steel: Carbon steel benefits, but less critical than for Al/SS. Less precise answer.

What is Leg length in a Fillet Weld?

Leg length is the distance from the root of the weld to the toe. There shall be two legs in a fillet joint. Refer below photograph where there is a leg at the horizontal direction and another one is in the vertical plane. Leg length is often denoted by the letter ‘Z’.

What is Throat Thickness in a Fillet Weld?

The throat thickness (or throat size) is another important measurement in fillet welds. It is defined as the shortest distance from the root of the weld to the face of the weld. Throat thickness is significant because it directly affects how strong the weld will be. A thicker throat can carry more load before failing, making it an essential factor in welding design. Throat thickness is often denoted by the letter ‘a’.

The Relationship Between Leg Size and Throat Thickness

Now, let’s talk about how leg length and throat thickness are related. There are two key formulas that show this relationship, but it’s important to note that these formulas apply only when both legs of the fillet weld are equal in length:

1. Calculating Throat Thickness from Leg Size:
   • If you know the leg length, you can find out the throat thickness by using this formula:
   • a=0.707 x Z

Here, ‘a’ represents the throat thickness. This formula tells us that the throat thickness is about 70.7% of the leg length, which means that the throat thickness will always be less than the leg length.

1. Calculating Leg Size from Throat Thickness:
   • If you know the throat thickness,  you can find out the leg size by using this formula:
   • Z = 1.414 X a

We will illustrate this with some example questions.

Q1. In a fillet weld where both legs are equal, if the leg length is 8 mm, what is the throat thickness?

1. 4.0 mm
2. 5.0 mm
3. 5.66 mm
4. 6.66 mm

Correct Answer: 3) 5.66 mm

Explanation:

To find the throat thickness (a) from the leg length (Z), we use the formula:

a=0.707 X Z

Substituting leg length (Z) = 8 mm in the above formula;

a =0.707×8 = 5.656 mm

Thus, the throat thickness is 5.656 mm which will approximately equal to 5.66 mm

Q2. In a fillet weld where both legs are equal, if the throat thickness is 6 mm, what is the corresponding leg length?

1. 7.0 mm
2. 8.484 mm
3. 9.34 mm
4. 10.0 mm

Correct Answer: 2) 8.484 mm

Explanation:

To find the leg length (Z) from the throat thickness (a), use the formula:

Z = 1.414 X a

Substituting throat (a) = 6 mm in the above formula;

Z = 1.414 X 6

Thus, the throat thickness is 8.484 mm.

1. To connect different sections of piping
2. To increase the speed of fluid flow
3. To reduce noise from fluid movement
4. To make pipes look nicer

Explanation: Pipe fittings play a vital role in constructing robust and efficient piping networks across residential, commercial, and industrial applications. Here’s why we use them:

1. Connecting Different Sections: Pipe fittings allow us to join pipes together, creating a continuous flow path. Whether it’s joining straight sections or navigating corners, fittings like couplings and unions ensure a secure connection.
2. Changing Direction: Elbows and tees help us change the flow direction within the piping system. Need to go around obstacles or make a right-angle turn? Elbows have got you covered.
3. Adjusting Diameter: Reducers and expanders come into play when connecting pipes of varying sizes. Concentric reducers maintain centerlines, while eccentric reducers prevent air accumulation.
4. Blocking Flow: Caps and plugs seal off the end of a pipe, preventing unwanted flow or leaks.
5. Controlling Flow: Valves, another type of fitting, regulate fluid flow. Whether it’s opening, closing, or adjusting the flow rate, valves keep things under control.

So, the correct answer is 1. To connect different sections of piping.

Remember, pipe fittings are like the unsung heroes of plumbing and piping systems—they quietly ensure everything flows smoothly! (www.weldingandndt.com)

Q2. Which welding process is famous for producing high-quality welds with minimal distortion?

1. Shielded Metal Arc Welding (SMAW)
2. Gas Tungsten Arc Welding (GTAW)
3. Flux-Cored Arc Welding (FCAW)
4. Submerged Arc Welding (SAW)

Explanation: When it comes to producing top-notch welds with minimal distortion, Gas Tungsten Arc Welding (GTAW), also known as TIG welding, is the standout choice. This process uses a non-consumable tungsten electrode to create a precise arc, allowing for exceptional control over the weld pool. It’s perfect for applications where quality and appearance matter, like in aerospace or automotive industries. Let’s look at the other options:

• Shielded Metal Arc Welding (SMAW): Also known as stick welding, this process is versatile and easy to learn but can produce more distortion and slag compared to GTAW.
• Flux-Cored Arc Welding (FCAW): This method is great for thicker materials and outdoor work since it uses a tubular wire filled with flux. However, it may not provide the same level of precision as GTAW.
• Submerged Arc Welding (SAW): This process is ideal for thick materials and large-scale applications but can be less precise than TIG welding and is typically used in industrial settings.

So the correct answer is 2. Gas Tungsten Arc Welding (GTAW)

So, if you’re looking for a welding process that delivers high-quality results with minimal distortion, GTAW is definitely the way to go! It’s all about getting that perfect weld every time.

Q3. Which type of pump is best for moving large amounts of liquid at low pressure?

1. Centrifugal pump
2. Positive displacement pump
3. Gear pump
4. Diaphragm pump

Explanation: When it comes to efficiently moving large volumes of liquid at low pressure, centrifugal pumps are your best bet. These pumps work by using a rotating impeller to create a flow that pushes the liquid through the system. They’re perfect for applications like water supply, irrigation, and chemical transfer because they handle thin liquids like water and solvents exceptionally well. But what about the other types of pumps? Here’s a quick rundown:

• Positive Displacement Pumps: These pumps excel at moving high-viscosity fluids and can maintain a constant flow regardless of pressure changes. They’re ideal for applications involving thick oils or slurries but aren’t as efficient for large volumes at low pressure.
• Gear Pumps: A type of positive displacement pump, gear pumps use rotating gears to move fluid. They’re great for transferring oil or other viscous liquids but can struggle with lower viscosity fluids.
• Diaphragm Pumps: These are also positive displacement pumps that use a flexible diaphragm to push fluid. They’re excellent for handling corrosive or shear-sensitive liquids, making them popular in chemical processing.

So the correct answer is 1. Centrifugal pump

In summary, while centrifugal pumps are fantastic for high-volume, low-pressure applications, each pump type has its strengths depending on the specific needs of your project. Whether you’re dealing with thick fluids or need precise dosing, understanding these differences can help you choose the right pump for the job! (www.weldingandndt.com)

Q4. Which mechanical property tells you how much energy a material can absorb before it breaks?

1. Hardness
2. Ductility
3. Brittleness
4. Toughness

Explanation: When we talk about toughness, we’re referring to a mechanical property that indicates how much energy a material can absorb before it fractures. Think of it as a material’s ability to take a hit without breaking apart. Tough materials are essential in applications where impact resistance is crucial, such as in construction or automotive parts. Let’s look at the other options:

• Hardness measures how resistant a material is to scratching or denting. While hard materials can withstand surface damage, they might not handle impacts well.
• Ductility refers to how much a material can stretch or deform without breaking. Ductile materials can absorb some energy, but they might not be as tough under sudden stress.
• Brittleness is the opposite of toughness. Brittle materials can be strong but tend to shatter easily when subjected to stress, like glass or ceramics.

So the correct answer is 4. Toughness

Understanding these mechanical properties helps engineers and designers choose the right materials for their projects. So, if you’re looking for a material that can handle some serious abuse before giving way, toughness is what you want to keep an eye on! (www.weldingandndt.com)

Q5. What’s the primary job of an electric motor?

1. To convert electrical energy into mechanical energy
2. To generate electrical energy from motion
3. To store electrical energy for later use
4. To regulate voltage in a circuit

Explanation: The main job of an electric motor is to convert electrical energy into mechanical energy. This means it takes the electricity you supply and turns it into motion—think about how your washing machine or electric fan works! Here’s a quick look at what the other options mean:

• To generate electrical energy from motion: That’s actually what a generator does. While motors and generators are similar in design, they serve opposite functions. Motors use electricity to create movement, while generators do the reverse.
• To store electrical energy for later use: This describes batteries or capacitors, not motors. Electric motors need a constant power supply to function.
• To regulate voltage in a circuit: That’s more about devices like voltage regulators or transformers. Motors are all about converting power into motion!

So the correct answer is 1. To convert electrical energy into mechanical energy

Electric motors are everywhere—from industrial machines to household appliances—making our lives easier and more efficient. So next time you flip a switch or plug something in, remember that electric motors are working hard behind the scenes to get things moving!

Q6. Which type of stress is caused by forces pulling a material apart, like a rubber band being stretched?

1. Compressive stress: The material is being squeezed together
2. Tensile stress: The material is being pulled apart
3. Shear stress: The material is being twisted or slid past each other
4. Bending stress: The material is being bent or flexed

Explanation: When a material is subjected to forces that pull it apart, it experiences tensile stress. This is similar to stretching a rubber band.

• Compressive stress occurs when a material is pushed together, like squeezing a sponge.
• Shear stress occurs when a material is subjected to forces that cause it to slide or twist, like cutting a piece of paper with scissors.
• Bending stress occurs when a material is subjected to forces that cause it to bend or flex, like a diving board.

So the correct answer is: 2. Tensile stress: The material is being pulled apart

Understanding the different types of stress is essential for engineers and designers to ensure that materials are used appropriately and can withstand the forces they will be subjected to.

Q7. What do we call the process that involves heating a material to a specific temperature and then slowly cooling it down to relieve internal stresses?

1. Annealing
2. Quenching
3. Tempering
4. Normalizing

Explanation: Annealing is a game-changing heat treatment process that plays a vital role in metallurgy. It involves heating a material—typically metal—to a specific temperature and then allowing it to cool gradually. This slow cooling helps eliminate internal stresses that can develop during processes like forging or welding. By doing this, annealing enhances the material’s ductility, making it easier to shape and work with, while also improving its overall structural integrity. Think of it as giving the metal a chance to unwind and reorganize itself, resulting in a more uniform and stable product.

So the correct Answer is: 1.Annealing

What About the Other Options?

• Quenching takes a different approach! In this process, a material is heated to a high temperature and then rapidly cooled by plunging it into water, oil, or another cooling medium. This quick cooling hardens the material significantly but can also introduce internal stresses due to the rapid temperature change. Quenching is commonly used for hardening steel and alloys, making them ideal for tools and applications where strength is crucial.
• Next up is tempering, which usually follows quenching. After hardening the material through quenching, it’s reheated to a lower temperature and allowed to cool again. This step reduces brittleness while retaining some of the hardness gained from quenching. Tempering is essential for achieving that perfect balance between strength and toughness, ensuring materials can withstand impact without breaking.
• Finally, we have normalizing. This process is similar to annealing but typically involves heating the material to a higher temperature before allowing it to cool in air. Normalizing refines the grain structure of the metal, resulting in improved mechanical properties and uniformity throughout. It’s often used for steel components that require enhanced toughness and strength while ensuring consistent performance across the entire piece.

Conclusion: Grasping these heat treatment processes—annealing, quenching, tempering, and normalizing—can significantly boost your understanding of materials science and engineering. Each method has its unique purpose in optimizing material properties for various applications. So go ahead, share this knowledge with your friends and colleagues; it’s bound to spark engaging conversations in any engineering or manufacturing setting! (www.weldingandndt.com)

Q8. In fluid mechanics, what does the term “head loss” refer to?

1. The height difference between two points in a pipeline
2. The volume of fluid lost during a leak
3. The loss of energy due to friction and turbulence in a pipe
4. The pressure drop across a valve

Explanation: Head loss is a fundamental concept in fluid mechanics that describes the reduction in the total energy (or “head”) of a fluid as it flows through a piping system. This loss can occur due to several factors, primarily friction and turbulence.

• Friction Loss: As fluid moves through a pipe, it encounters resistance from the pipe walls. This resistance is caused by the viscosity of the fluid and the roughness of the pipe’s interior surface. The greater the length of the pipe and the roughness of its surface, the more energy is lost to friction.
• Turbulence: Turbulent flow occurs when the fluid’s velocity is high enough that it creates chaotic eddies and vortices, which further dissipate energy. When fluid flows through fittings, bends, and valves, it can become turbulent, leading to additional energy losses.
• Total Head: The term “head” refers to the energy per unit weight of the fluid, typically expressed in terms of height (like meters or feet). It includes three components: elevation head (height above a reference point), pressure head (pressure energy), and velocity head (kinetic energy). Head loss reduces this total head as fluid travels through the system.

Calculating head loss is essential for ensuring that pumps are appropriately sized to overcome these losses and maintain desired flow rates. Engineers often use the Darcy-Weisbach equation to quantify head loss, which relates it to factors such as flow velocity, pipe diameter, length, and friction factor.

So the correct answer is: 3. The loss of energy due to friction and turbulence in a pipe

Understanding head loss is crucial for engineers when designing piping systems. It helps them ensure that pumps are adequately sized to overcome these losses and maintain desired flow rates. By calculating head loss, engineers can optimize system performance and efficiency, preventing issues like inadequate pressure at delivery points or excessive energy consumption. So next time you think about how fluids move through pipes, remember that head loss is an essential factor that engineers must consider for efficient design and operation! Share this knowledge with your colleagues—it’s sure to spark some interesting discussions! (www.weldingandndt.com)

Q9. Which type of pipe fitting is used to join two pipes at a 90-degree angle?

1. Tee fitting
2. Elbow fitting
3. Reducer fitting
4. Coupling

Explanation: The 90-degree elbow fitting is a fundamental component in piping systems, specifically designed to connect two pipes at a right angle. This fitting is essential for directing the flow of fluids in various applications, from residential plumbing to complex industrial systems.

So the correct answer is: 2) Elbow fitting

Key Points About 90-Degree Elbow Fittings:

1. Purpose: The primary function of a 90-degree elbow is to change the direction of fluid flow by 90 degrees. This is particularly useful in tight spaces where a straight run of pipe cannot be maintained.
2. Types of Elbows:
   • Short Radius (SR) Elbow: This type has a tighter bend and is typically used where space is limited. However, it can create more turbulence and pressure drop compared to long radius elbows.
   • Long Radius (LR) Elbow: This type features a gentler curve, allowing for smoother fluid flow and reduced turbulence. It’s preferred in applications where maintaining flow efficiency is crucial. (www.weldingandndt.com)
3. Materials: 90-degree elbows can be made from various materials, including:
   • PVC (Polyvinyl Chloride): Commonly used in residential plumbing for its affordability and resistance to corrosion.
   • Copper: Often used in water supply lines due to its durability and antimicrobial properties.
   • Stainless Steel: Ideal for high-pressure and high-temperature applications, such as in chemical processing or oil and gas industries.
   • Cast Iron: Traditionally used in drainage systems for its strength and sound-dampening qualities.
4. Applications: These fittings are widely utilized across multiple sectors:
   • Plumbing: For routing water supply lines and drainage systems.
   • HVAC Systems: To direct airflow through ductwork.
   • Industrial Processes: In chemical plants and manufacturing facilities where precise fluid control is necessary.
5. Installation Considerations: When installing a 90-degree elbow, it’s important to consider the flow direction, potential pressure drops, and the overall layout of the piping system. Proper alignment and secure connections are essential to prevent leaks and ensure efficient operation.

Understanding the role of 90-degree elbow fittings in piping systems is crucial for engineers, plumbers, and technicians involved in design and installation. Their ability to effectively redirect flow while maintaining system integrity makes them indispensable components in both residential and industrial applications.

Q10. Which type of pump is best suited for handling highly viscous liquids with high solids content?

1. Centrifugal pump
2. Positive displacement pump
3. Gear pump
4. Diaphragm pump

Explanation: When it comes to pumping highly viscous liquids—such as oils, slurries, or any fluid containing a significant amount of solids—a positive displacement pump is often the best choice.

How Positive Displacement Pumps Work:

Positive displacement pumps operate by trapping a fixed volume of liquid and forcing it through the pump. This action creates a pressure differential that drives the liquid forward.

Why Positive Displacement Pumps are Ideal for Viscous Liquids and High Solids Content:

• Thick fluids: Positive displacement pumps can handle viscous liquids that are difficult to pump with centrifugal pumps.
• Solids handling: These pumps can handle liquids with suspended solids, such as slurries and sludge.
• Precise flow control: Positive displacement pumps can provide accurate and consistent flow rates, which is important in many industrial applications.
• Self-priming: Many positive displacement pumps are self-priming, meaning they can pump liquid from below their suction line.

So the correct answer is: 2. Positive displacement pump

Q11. Which type of pipe joint is most commonly used for joining pipes of the same diameter under high pressure and temperature conditions?

1. Socket weld joint
2. Flange joint
3. Butt weld joint
4. Grooved joint

Explanation: Butt weld joint is the most commonly used type of pipe joint for joining pipes of the same diameter under high pressure and temperature conditions. A butt weld joint is created by aligning the ends of two pipes and welding them together. This method provides a continuous and smooth flow path, which is crucial in high-pressure applications where any disruption in flow can lead to significant issues. 

Butt joints provide a strong and reliable connection with minimal flow restriction. They are widely used in various industries, including oil and gas, power generation, and chemical processing.

So the correct answer is: 3. Butt weld joint 

Q12. Which law of thermodynamics states that energy cannot be created or destroyed, only transferred or converted from one form to another?

1. First Law
2. Second Law
3. Third Law
4. Zeroth Law

Explanation: The First Law of Thermodynamics, often referred to as the Law of Conservation of Energy, is a fundamental principle in physics and engineering. It asserts that energy cannot be created or destroyed; it can only change forms or be transferred between systems. This law is crucial for understanding how energy operates within various physical processes and systems.

Key Concepts:

Energy Conservation: The First Law emphasizes that the total energy within a closed system remains constant. While energy can transform from one type to another—such as from kinetic energy (motion) to potential energy (stored energy)—the overall amount of energy does not change. This principle is foundational in fields like mechanical engineering, chemical engineering, and environmental science.

Mathematical Representation: The First Law can be mathematically expressed as:

ΔU = Q − W

Where;

• ΔU is the change in internal energy of the system.
• Q represents the heat added to the system.
• W is the work done by the system on its surroundings.

Applications: The First Law has numerous applications across various industries:

• Heat Engines: In automotive and power generation, understanding how energy is converted from fuel into mechanical work is essential for efficiency.
• Refrigeration: In HVAC systems, this law helps engineers design systems that effectively transfer heat to maintain desired temperatures.
• Chemical Reactions: It governs how energy is absorbed or released during chemical processes, which is critical for reaction kinetics and thermodynamics.

Real-World Examples:

• When you boil water on a stove, electrical energy (from the stove) is converted into thermal energy (heat), which increases the water’s internal energy until it turns into steam.
• In a car engine, chemical energy stored in gasoline is converted into mechanical energy to move the vehicle while also producing heat.

Limitations: While the First Law provides a framework for understanding energy conservation, it does not indicate the direction of energy transfer or the feasibility of certain processes. For instance, it does not explain why heat flows from hot to cold objects; this behavior is addressed by the Second Law of Thermodynamics.

So the correct answer is: 1. First Law

Q13. What is the key factor that determines how much liquid can flow through a pipe?

1. Pipe length
2. Pipe material
3. Pipe insulation
4. Pipe diameter

Explanation: When it comes to determining the flow capacity of a pipe, pipe diameter is the most critical factor. The diameter of a pipe directly influences the volume of liquid that can pass through it, making it a fundamental consideration in fluid dynamics and engineering design.

So the correct answer is: 4. Pipe diameter

Why Pipe Diameter Matters:

1. Flow Rate and Cross-Sectional Area: The flow rate of a liquid through a pipe is significantly affected by its cross-sectional area. A larger pipe diameter increases the area through which liquid can flow, allowing more fluid to pass simultaneously. This relationship is crucial in applications ranging from residential plumbing to industrial piping systems.
2. Bernoulli’s Principle: According to Bernoulli’s equation, as the diameter of a pipe increases, the velocity of the fluid decreases if the flow rate remains constant. This means that larger pipes can transport more liquid without increasing the speed of the flow, reducing friction losses and enhancing system efficiency.
3. Impact on Pressure Loss: A larger diameter pipe minimizes pressure losses due to friction. In contrast, smaller diameter pipes can lead to higher velocities and increased turbulence, which results in greater energy consumption and potential wear on the system over time.
4. Applications Across Industries: Understanding how pipe diameter affects flow is vital in various sectors:
   • Water Supply Systems: Engineers must select appropriate pipe sizes to ensure sufficient water pressure and flow rates for municipal distribution.
   • Oil and Gas Pipelines: In these industries, optimizing pipe diameter can lead to significant cost savings by reducing pumping energy requirements.
   • Chemical Processing: Accurate sizing of pipes is essential for maintaining safe and efficient operations when transporting hazardous materials.
5. Other Contributing Factors: While pipe diameter is paramount, other factors also play a role in determining flow capacity:
   • Pipe Length (Option B): Longer pipes introduce more frictional resistance, which can reduce flow rates.
   • Pipe Material (Option C): Different materials have varying roughness levels that affect friction; smoother materials generally allow better flow.
   • Pipe Insulation (Option D): While insulation primarily affects thermal properties rather than flow capacity, it can influence the viscosity of fluids at certain temperatures.

In summary, when designing piping systems or selecting pipes for specific applications, prioritizing pipe diameter is essential for optimizing liquid flow. Understanding this key factor helps engineers create efficient systems that minimize energy costs and improve overall performance.

Q14. Which material is commonly used for making cutting tools?

• High-speed steel
• Aluminum
• Copper
• Brass

(Explanation: High-speed steel (HSS) is the most commonly used material for manufacturing cutting tools due to its outstanding hardness and ability to maintain a sharp cutting edge even at elevated temperatures. This makes HSS ideal for high-speed machining operations, where tools are subjected to intense heat and stress. High-speed steel tools are extensively utilized in various industries, including manufacturing, automotive, and aerospace, because they offer superior wear resistance and long-lasting durability.)

Q15. A cylindrical container is filled with water. A spherical ball of ice is dropped into the water. As the ice melts, what happens to the water level in the container?

1. The water level rises
2. The water level falls
3. The water level remains the same
4. The water level depends on the size of the ice ball

(Explanation: When you drop a spherical ball of ice into a cylindrical container filled with water, the behavior of the water level is quite interesting. Initially, the ice floats because it is less dense than water. While the ice is floating, it displaces a volume of water equal to its weight. Since ice is less dense than liquid water, the volume of water displaced is greater than the volume of the ice itself. As the ice melts, it turns into water, and the volume of water produced from melting is exactly equal to the volume of water that was displaced when the ice was floating. Therefore, when you consider both the displacement caused by the floating ice and the volume of water created as it melts, you find that the overall water level in the container remains unchanged. In conclusion, the correct answer is that the water level remains the same.)

Q16. What is the most effective non-destructive testing (NDT) method for detecting internal defects in welded joints?

1. Visual Inspection (VI)
2. Magnetic Particle Testing (MPT)
3. Ultrasonic Testing (UT)
4. Liquid Penetrant Testing (LPT)

(Explanation: Ultrasonic Testing (UT) is widely used for detecting internal defects in welded joints. It uses high-frequency sound waves to identify imperfections within the material, making it highly effective for ensuring the integrity of welds. To learn more about Ultrasonic Testing (UT), please click here.)

Q17. A discontinuity that forms during the solidification of molten metal in casting processes is called:

1. Processing
2. Service
3. Inherent
4. None of the above

(Explanation: Inherent discontinuities occur naturally during the initial formation of the metal, often due to factors like shrinkage or gas entrapment. Processing discontinuities arise during manufacturing processes, and service discontinuities develop during the metal’s use in service.)

Q18. A lamination in a steel plate would be classified as what type of discontinuity?

1. Service
2. Inherent
3. Processing
4. None of the above

(Explanation: Laminations are discontinuities that occur during the manufacturing process of steel plates, often due to rolling or other forming operations. Inherent discontinuities occur during the initial formation of the metal and service discontinuities develop during the metal’s use.)

Q19. Cracks caused by alternating stresses above a critical level are called:

1. Stress corrosion cracks
2. Cycling cracks
3. Critical cracks
4. Fatigue cracks

(Explanation: Fatigue cracks develop due to repeated cyclic stresses that exceed the material’s endurance limit, leading to progressive and localized structural damage. Other options are less suitable: stress corrosion cracks result from the combined effect of tensile stress and a corrosive environment, cycling cracks is not a standard term, and critical cracks do not specifically refer to the mechanism of formation.)

Q20. When comparing grey cast iron with low carbon steel, which of the following is correct?

1. Weldability is poor
2. Less brittle
3. Higher tensile strength
4. Poor machinability

(Explanation: Grey cast iron has poor weldability because of its high carbon content and brittle nature, which leads to cracking during welding. (www.weldingandndt.com) It is actually more brittle and weaker in tension than low carbon steel. However, its machinability is good, since the graphite flakes in the structure act as natural chip breakers and lubricants.)

Q21. Steel composition is changed from 0.25% carbon and 0.8% chromium to 0.35% carbon and 1.5% chromium. Which of the following is correct?

1. Hardness in the heat-affected zone (HAZ) increases
2. Risk of hydrogen cracking decreases
3. Toughness at low temperature increases
4. Machinability improves

(Explanation: Raising carbon and chromium content increases the hardenability of the steel. This makes the HAZ harder because martensitic structures are more likely to form on cooling. However, with higher hardness, the steel also becomes more prone to hydrogen-induced cracking, loses toughness at low temperature, and becomes harder to machine.)

Q22. A hydrotest of a plant pipe spool shows a pressure drop of 5% after 1 hour (design pressure test). The QA engineer discovers all gauges/calibrations are in order. What next?

1. Accept because 5% drop is acceptable.
2. Immediately condemn the spool.
3. Investigate for undetectable micro-leaks, trapped air, and retest.
4. Reduce test time to 30 minutes to save schedule.

(Explanation: A 5% pressure drop during hydrotesting is not considered acceptable by most standards, which typically allow zero pressure loss over the required test period. If all gauge calibrations are verified, the drop may be due to trapped air, undetectable micro-leaks, or temperature changes. The pipe spool should not be accepted or condemned immediately; thorough investigation is necessary to identify the cause and to retest after corrective actions. Reducing test time would compromise safety and code compliance. Always refer to project specifications and industry codes before final acceptance.)

Q23. When welding Inconel alloys (600, 601, or 690) to stainless steel or carbon steel, which filler metal is most appropriate to ensure metallurgical compatibility and crack resistance?

1. ER309L
2. ERNiCr-3 (Inconel 82)
3. ERNiCrMo-3 (Inconel 625)
4. ERNiCu-7 (Monel filler)

(Explanation: For joining Inconel (Ni-based) to SS or CS, ERNiCr-3 gives the best dilution control and resistance to solidification cracking. 309L can lead to hot cracks due to ferrite imbalance, and 625 is too rich in Mo for this pairing. That’s why most WPSs for Inconel-to-SS/CS specify Inconel 82 filler.)

1. To outline the general requirements for welding
2. To outline the general requirements for brazing
3. To outline the general requirements for plastic fusing
4. All of the above

(Explanation: ASME Section IX, Part QG, is designed to cover the general requirements for various material-joining processes, including welding, brazing, and plastic fusing. This ensures that the standards are comprehensive and applicable to different types of joining methods, providing a unified approach to quality in these processes.)

 Q2. What is the primary purpose of a Welding Procedure Specification (WPS) as per ASME Section IX?

1. To list the materials used in welding
2. To provide a detailed plan for producing a weld that meets code requirements
3. To document the qualifications of the welder
4. To specify the cost of welding operations

(Explanation: The primary purpose of a Welding Procedure Specification (WPS) is to ensure that the welding process produces a weld that meets the required standards and specifications. This document is crucial for maintaining quality and safety in welding operations, making it a frequently searched topic among welding professionals and engineers.)

Q3. Which of the following variables are generally considered as an essential variable in a WPS as per ASME Section IX?

1. Welder’s experience, type of welding machine, and cost of welding materials
2. Type of welding machine, cost of welding operations, and welder’s certification
3. Base material, filler material, P Number and preheat temperature
4. Welding position, welding electrode, P number and welder’s experience

(Explanation: Essential variables in a WPS are critical factors that can affect the mechanical properties of the weld. These include base material, filler material, P number and preheat temperature.)

Q4. In which position a welder can weld in groove welds (in plate and pipe over 24″ OD), if he is qualified in 4G position (As per ASME section IX)?

1. All positions
2. Flat and Overhead
3. Overhead
4. Flat, Vertical and Overhead

(Explanation: According to Table QW-461.9 of ASME Section IX, a welder qualified in the 4G position can weld in the flat and overhead positions for plate and pipe over 24″ O.D.)

Q5. A welder qualified with plate fillet welds in the 3F and 4F positions is qualified to weld groove welds in plate in which positions?

1. Flat
2. Flat and Vertical
3. Vertical and Overhead
4. None of the above

 (Explanation: According to Table QW-461.9 of ASME Section IX, a welder qualified in the 3F and 4F positions for plate fillet welding is not qualified to perform groove welds. www.weldingandndt.com)

Q6. When a tensile test specimen breaks in the base metal outside of the weld or fusion line, the tensile strength (UTS) recorded may be at the most how much below the specified tensile strength to be accepted as per ASME section IX?

1. 5%
2. 10%
3. 15%
4. Cannot be accepted if it breaks below the specified minimum tensile strength

(Explanation: According to QW-153.1(d), if the specimen fractures in the base metal outside of the weld or fusion line, the test will be considered acceptable as long as the recorded strength does not fall more than 5% below the minimum specified tensile strength of the base metal.)

Q7. The acceptance criteria for radiography tests of welder qualification test can be found in which of the following ASME codes?

1. ASME Section IX
2. ASME Section VIII Div. 1
3. ASME Section VI
4. The referencing code

(Explanation: The acceptance criteria for radiographic testing used in welder qualification is specified in ASME Section IX. QW-191.1.2)

Q8. If a WPS was qualified under the 1965 edition of ASME Section IX, can it still be used today?

1. Yes, it remains valid
2. No, it must be requalified to the current code
3. It can only be used for 1965-era pressure vessels
4. It is limited to repair welding, not new construction

(Explanation: As per QG-108 of ASME Section IX, Joining procedure specifications, procedure qualifications, and performance qualifications established in accordance with earlier editions or addenda of this section may be utilized for any construction where the current edition has been specified. www.weldingandndt.com)

Q9. If a welder was qualified in the SMAW process on January 1, 2023, and last performed welding with SMAW on March 30, 2023, will he still be qualified on October 15, 2024?

1. Yes
2. No
3. Yes, but with close monitoring
4. Yes, but only for non-critical jobs first

(Explanation: As per QW-322.1 of ASME Section IX, A welder’s qualification is only valid for 6 months from the time they last performed welding with that process. In this case, since the welder last welded with SMAW on March 30, 2023, their qualification would have expired on September 30, 2023 (6 months later). Therefore, on October 15, 2024, the welder would no longer be considered qualified for the SMAW process. Hence, the welder would need to pass a new welder qualification test or retest.)

Q10. What is the key difference between test positions 2F and 2FR for fillet welds in pipes?

1. In 2F, the pipe axis remains vertical, while in 2FR, the pipe axis remains horizontal and the pipe is rotated during welding.
2. In 2F, the pipe axis remains horizontal, while in 2FR, the pipe axis remains vertical and the pipe is rotated during welding
3. The pipe axis remains horizontal in both positions (2F & 2FR). However, the pipe is rotated in 2FR.
4. None of the above

(Explanation: In 2F position, the pipe’s axis is vertical, which means that the welder works on a horizontal weld joint located at the top of the vertical pipe. The welding process is performed without rotating the pipe, allowing for a fixed position for the welder. However, in 2FR position, the pipe’s axis is horizontal, and the axis of the deposited weld in the vertical plane. The pipe is rotated during welding. This allows for the pipe to be rotated during the welding process, which can make it easier for the welder to maintain a consistent weld bead and improve access to the joint.) (www.weldingandndt.com)

Q11. What is the acceptance criteria for porosity (rounded indication) in a welder qualification test according to ASME Section IX?

1. 1/8 inch (3 mm) maximum
2. 20% of the total weld thickness (excluding any reinforcement) or 1/8 inch (3 mm), whichever is smaller (
3. 30% of the total thickness or 1/2 inch (12.5 mm), whichever is smaller
4. None of the above

(Explanation: As per QW-191.1.2.2 (b)(2)(-a) of ASME Section IX, The maximum permissible dimension for rounded indications shall be 20% of the thickness of the weld, excluding any allowable reinforcement, or 1/8 in. (3 mm), whichever is smaller. For a groove weld joining two base metals having different thicknesses at the weld, the thickness is the thinner of the two base metals being joined.

Example: Consider a groove weld joining two base metals with thicknesses of 1 in. (25 mm) and 3/4 in. (19 mm). The thickness of the weld, excluding any allowable reinforcement, is the thinner base metal, which is 3/4 in. (19 mm). 

Calculation of Maximum Permissible Dimension for Rounded Indications:

1. 20% of Weld Thickness:
   • 20% of 3/4 in. = 0.15 in. (approximately 3.8 mm)
2. Comparison with 1/8 in. (3 mm):
   • Since 1/8 in. (3 mm) is smaller than 0.15 in. (3.8 mm), the maximum permissible dimension for rounded indications is 1/8 in. (3 mm).

This means that any rounded indications (such as porosity) found in the weld must not exceed 1/8 in. (3 mm) in size to meet the acceptance criteria. )

Q12. Which clause in ASME Section IX specifies that a Welding Procedure Specification (WPS) qualified for plate welding can also be used for pipe welding?

1. Clause QW-201
2. Clause QW-202
3. Clause QW-211
4. There is no such clause in ASME section IX

(Explanation: ASME Section IX, clause QW-211, states that qualification in plate welding also qualifies a WPS for pipe welding and vice versa. This means that a WPS qualified for welding on plates is also qualified for welding on pipes, and the same applies in reverse.)

Q13. A Welding Procedure Specification (WPS) was qualified by conducting a Procedure Qualification Test (PQT) in the 1G position. Can that WPS be qualified for all positions? 

1. No, the WPS can only be qualified for the 1G position
2. Yes, the WPS can be qualified for all positions including overhead position
3. The WPS can be qualified for all positions except 6G, as the 1G PQT is insufficient for 6G qualification.
4. The WPS can be qualified for all positions in fillet joint. However, only flat position in groove joints.

(Explanation: According to QW-203 of ASME Section IX, if a Procedure Qualification Test (PQT) is conducted in any position (such as 1G), the resulting Welding Procedure Specification (WPS) can be qualified for all positions. However, it is essential that the welding process and electrodes used are appropriate for the positions allowed by the WPS.)

Q14.  A welder has passed the welder qualification test in 3G and 4G positions on a groove welded joint test coupon prepared from a 16 mm thick mild steel (MS) plate. In which of the following positions is he qualified to perform fillet welding on both plate and pipe? (www.weldingandndt.com)

1. All Positions
2. Flat & Vertical
3. Flat, Vertical & Horizontal
4. Vertical Only

(Explanation: As per table QW-461.9 of ASME Section IX, A welder qualified with 3G & 4G position can weld all positions in fillet joints on both plates and pipes).

Q15.  A welder has passed the performance qualification test (WQT) in 3G and 4G positions on a groove welded joint test coupon prepared from a 16 mm thick mild steel (MS) plate. In which of the following positions is he qualified to perform groove joint on plate? (www.weldingandndt.com)

1. All Positions
2. Flat & Vertical
3. Flat, Vertical & Overhead
4. Vertical Only

(Explanation: As per table QW-461.9 of ASME Section IX, A welder qualified with 3G & 4G position can weld flat, vertical & overhead positions in groove joints on plates).

Q16.  If a welder deposited 12 mm thick weld (with three layers) on a 16 mm thick test coupon during qualification test, what is the maximum thickness he is qualified to weld? (www.weldingandndt.com)

1. 24 mm
2. 12 mm
3. Can’t be qualified
4. Unlimited

(Explanation: As per Table QW-452.1(b) – ASME Section IX, Thickness of Weld Metal Qualified is “2t” Where “t ” is thickness of the deposited weld metal in the coupon during the welder qualification (performance qualification) test. Hence, if the welder has deposited 12 mm thick weld during the test, he/she can weld upto a thickness of 24 mm i.e. 2t = 2X12 mm = 24 mm. www.weldingandndt.com)

Q17.  If a welder deposited 16 mm thick weld (with four layers) on a 20 mm thick test coupon during qualification test, what is the maximum thickness he is qualified to weld?

1. 32 mm
2. 16 mm
3. Can’t be qualified
4. Maximum to be welded
5. Unlimited

(Explanation: As per Table QW-452.1(b) in ASME Section IX, if a welder deposits weld metal that is 13 mm or thicker (with a minimum of three layers), he qualifies for maximum thickness specified in the Welding Procedure Specification (WPS). Given that the welder deposited 16 mm with four layers, which exceeds both the 13 mm thickness and the requirement of three layers, he qualifies to weld the maximum thickness specified in the Welding Procedure Specification. www.weldingandndt.com)

Q18. According to ASME Section IX, which of the following sets of positions represents the standard fillet weld pipe welding positions?

1. 1F, 2F, 3F & 4F
2. 1G, 2G, 5G & 6G
3. 1F, 2F, 2FR, 4F & 5F
4. 1F, 2F, 2FR, 4F & 6F

(Explanation: As per QW-132 – Pipe Positions, the fillet pipe positions are as follows: Flat Position 1F, Horizontal Positions 2F and 2FR, Overhead Position 4F, and Multiple Position 5F. To learn more about the welding positions, please read this article: https://www.weldingandndt.com/welding-positions/).

Q19. When is a change in a PQR permitted under ASME Section IX?

1. Changes to PQR is not permitted
2. To match WPS requirements
3. To correct the typing errors
4. To change the errors during the welding of the test coupon
5. Changes can be done to non essential variables only

(Explanation: As per QW200.2(C), Changes to the PQR are not permitted except editorial corrections or addenda to the PQR)

Q20. Which type of variables in a WPS affect the mechanical properties of a weldment?

1. Essential variables
2. Non-essential variables
3. Supplementary parameter variables
4. Administrative variables

(Explanation: As per QW-251.2 Any change in essential variable is considered to affect the mechanical properties of the weldment and therefore shall require requalification of the WPS.)

Q21. What is the UNS No. of SA516 Gr.70?

1. 70,000 Psi
2. UNS 516 G 70
3. K02700
4. K51670
5. UNS numbers are not assigned to ASTM/ASME materials

(Explanation: UNS number for any material can be found in Table QW/QB-422 of ASME section IX. The UNS number for SA 516 Grade 70 is K02700 as per Table QW/QB-422)

Q22. A 25mm to 25mm (P-No.1) coupon was welded entirely by the SMAW process during procedure qualification test. What will be the thickness qualification range (minimum qualified thickness and maximum qualified thickness) of the qualified WPS?

1. 5 mm – 50 mm
2. 1.5 mm – 50 mm
3. 25 mm – 50 mm
4. Upto 50 mm

(Explanation: For WPS thickness range, we need to refer table QW-451.1 in ASME Section IX. As per the table QW-451.1, for a 25 mm test coupon the minimum qualified thickness will be 5 mm and the maximum qualified thickness will be 2T i.e 2 X 25 = 50 mm.)

Q23. A welder qualified for 6G position on a 2″ (50 mm) pipe is assigned to weld a 10″ pipe in horizontal position. Is this acceptable?

1. Yes
2. Welder can weld all position but upto 4″ dia only.
3. Welder can weld all position but upto 2″ dia only.
4. Welder needs to be requalied with a 10″ dia pipe.

(Explanation: To solve this question you need to refer two tables, Namely;

1. QW-461.9: For position requirement
2. QW-452.3: For diameter range requirements.

Now as per table QW-461.9, Any welder qualified in 6G position can weld any position and as per table QW-452.3, any welder qualified on a 2″ (50 mm) pipe will be qualified to weld 1″ (25 mm) to unlimited diameter pipe. hence the answer will be “YES”.)

Q24. While reviewing a WPS, you find that it was qualified using SMAW process on 12 mm thick plate, but the job requires welding 40 mm thick plates using GTAW + SMAW combination. The correct action is:

1. Approve since both processes are qualified individually.
2. Qualify a new PQR with both processes combined.
3. Approve by increasing preheat to 200 °C.
4. Reduce the number of passes to avoid requalification.

(Explanation: When we qualify a WPS on a 12 mm thick plate, we can do job on the job for thicknesses up to 2 times of that means up to 24 mm. If the job needs to weld a thicker plate, like 40 mm, the current qualification is not enough, and we must do a new PQR for that thicker plate.

Also, in the question, the welding process is changing from just SMAW to a combination of GTAW and SMAW. Even if the original test had been done on a 40 mm plate, changing the welding process means we still need a new PQR to cover the combined processes.

1. Increases resistance to pitting and crevice corrosion
2. Enhances hardness and wear resistance
3. Improves thermal conductivity
4. Reduces ductility and toughness

Answer: 1. Increases resistance to pitting and crevice corrosion

(Explanation: The addition of molybdenum in stainless steel grade 316 (SS316) enhances its corrosion resistance compared to SS304. Molybdenum improves the alloy’s resistance to various forms of corrosion, including pitting and crevice corrosion, making SS316 more suitable for harsh environments such as marine and chemical processing applications.)

Q2. Why is SS316 commonly used in marine applications?

1. Due to its lightweight properties
2. For its high-temperature strength
3. Because of its excellent corrosion resistance in seawater
4. For its magnetic properties

Answer: 3. Because of its excellent corrosion resistance in seawater

(Explanation: In marine environments, the composition of stainless steel plays a crucial role in determining its corrosion resistance. Stainless steel grade 304, while generally resistant to environmental damage, including intergranular corrosion, is not recommended for prolonged exposure to seawater due to its susceptibility to chloride-induced corrosion. The molecular composition of 304 stainless steel provides protection against various environmental factors, with chromium enhancing its resistance in oxidizing environments and nickel protecting it from organic acids. However, the high chloride content in seawater makes SS304 vulnerable to corrosion in such conditions. For marine applications where resistance to chloride-induced corrosion is paramount, SS316 stainless steel is preferred due to the addition of 2% molybdenum. This extra element significantly enhances the material’s effectiveness in marine environments by improving its resistance to pitting and crevice corrosion caused by chloride exposure.)

Q3. What is the primary advantage of using SS304L over SS304 in corrosive environments?

1. Higher strength
2. Improved ductility
3. Enhanced resistance to intergranular corrosion
4. Better thermal conductivity

Answer: 3. Enhanced resistance to intergranular corrosion

(Explanation: SS304L offers improved resistance to intergranular corrosion compared to SS304 due to its lower carbon content, which reduces the formation of chromium carbides along grain boundaries. This enhanced resistance makes SS304L a preferred choice in corrosive environments where intergranular corrosion is a concern, regardless of temperature conditions.)

Q4. What role does nitrogen play in enhancing the properties of duplex stainless steels like SAF 2205?

1. Increases hardness and strength
2. Improves weldability and toughness
3. Enhances resistance to chloride stress corrosion cracking
4. Reduces the risk of sensitization

Answer: 3. Enhances resistance to chloride stress corrosion cracking

(Explanation: Nitrogen plays a crucial role in enhancing the properties of duplex stainless steels, such as SAF 2205. Duplex stainless steels are characterized by their balanced composition of austenitic and ferritic phases, which provide a combination of strength and corrosion resistance. Nitrogen is added to these steels to improve their resistance to chloride stress corrosion cracking (CSCC). www.weldingandndt.com

CSCC is a type of corrosion that occurs when a material is subjected to both tensile stress and a corrosive environment containing chlorides. The addition of nitrogen to duplex stainless steels helps to increase the pitting resistance equivalent number (PREN), which is a measure of a material’s resistance to pitting and crevice corrosion. This enhanced resistance to CSCC makes duplex stainless steels like SAF 2205 more suitable for applications where both strength and corrosion resistance are essential.)

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Q5. In what applications is Inconel 625, a nickel-based superalloy, commonly used?

1. High-temperature aerospace components
2. Food processing equipment
3. Structural welding in buildings
4. Marine applications

Answer: 1. High-temperature aerospace components

(Explanation: Inconel 625 is a nickel-based superalloy that is highly resistant to corrosion and oxidation, making it an excellent choice for high-temperature applications. It is commonly used in aerospace components, such as jet engines, where it is exposed to extreme temperatures and corrosive environments. Inconel 625’s high strength and resistance to thermal degradation make it ideal for these applications, as it can maintain its mechanical properties under high-temperature conditions. Additionally, its resistance to pitting and crevice corrosion makes it suitable for marine environments, where seawater can cause corrosion in other materials. Overall, Inconel 625 is a versatile material that can withstand harsh conditions, making it a popular choice for a variety of high-performance applications.)

Q6. How does the addition of chromium enhance the corrosion resistance of stainless steels?

1. Increases hardness
2. Forms a passive oxide layer
3. Improves thermal conductivity
4. Enhances ductility

Answer: 2. Forms a passive oxide layer

(Explanation: Chromium is a key element in the composition of stainless steels, and it plays a crucial role in enhancing their corrosion resistance. When chromium is present in sufficient quantities (usually above 10.5%), it forms a passive oxide layer on the surface of the material. This oxide layer acts as a protective barrier, preventing the underlying metal from coming into direct contact with the corrosive environment. As a result, the material is less susceptible to corrosion, making it suitable for applications where resistance to environmental degradation is essential. www.weldingandndt.com)

Q7. What is the primary advantage of using titanium in aerospace applications?

1. High thermal conductivity
2. Low density
3. Corrosion resistance
4. Electrical conductivity

Answer: 2. Low density

(Explanation: Titanium is widely used in aerospace applications due to its low density compared to other metals. Its low density allows for the design of lighter components, which can significantly reduce the overall weight of an aircraft. This weight reduction leads to increased fuel efficiency, reduced operating costs, and improved performance. Additionally, titanium’s high strength-to-weight ratio, excellent corrosion resistance, and good fatigue properties make it an ideal material for aerospace applications.)

Q8. What role does molybdenum play in improving the corrosion resistance of stainless steels?

1. Enhances pitting resistance
2. Increases electrical conductivity
3. Reduces ductility
4. Improves thermal expansion properties

Answer: 1. Enhances pitting resistance

(Explanation: Molybdenum is an important alloying element in many stainless steels, and it plays a significant role in improving the material’s resistance to pitting corrosion. Pitting corrosion is a type of localized corrosion that occurs in specific areas of a material, often due to the presence of chloride ions. (www.weldingandndt.com) Molybdenum helps to increase the pitting resistance equivalent number (PREN) of a stainless steel, which is a measure of the material’s resistance to pitting corrosion. By increasing the PREN, molybdenum helps to make the material more resistant to pitting corrosion, making it more suitable for applications where corrosion resistance is essential.)

Q9. Which coating method provides the highest level of corrosion protection for steel structures exposed to harsh environments?

1. Powder coating
2. Thermal spray coating
3. Anodizing
4. Galvanizing

Answer: 4. Galvanizing

(Explanation: Galvanizing is a coating method that offers exceptional corrosion protection for steel structures exposed to harsh environments. In galvanizing, steel components are coated with a layer of zinc through a hot-dip process or electroplating. The zinc coating acts as a sacrificial anode, providing cathodic protection to the underlying steel by corroding preferentially. (www.weldingandndt.com) This sacrificial protection effectively shields the steel from corrosion caused by exposure to moisture, chemicals, and other environmental factors. Galvanized coatings are known for their durability, longevity, and superior resistance to rust and corrosion, making them ideal for applications where extended protection against harsh conditions is essential.)

Q10. Which of the following surface preparation methods is most effective for removing heavy rust and scale from metal surfaces?

1. Solvent cleaning
2. Power tool cleaning
3. Abrasive blasting
4. Pickling

Answer: 3. Abrasive blasting

(Explanation: Abrasive blasting is a highly efficient method used to clean metal surfaces by forcibly propelling abrasive materials against them. When heavy rust and scale are present, abrasive blasting is particularly effective because it can dislodge and remove these stubborn contaminants, leaving behind a clean surface. During the process, abrasive media, such as sand, grit, or steel shot, is propelled at high velocity using compressed air or water. The impact of these abrasive particles on the surface effectively breaks down rust, scale, old paint, and other surface contaminants, preparing the metal for coating or painting. Abrasive blasting is widely used in industries such as construction, automotive, marine, and aerospace for its ability to achieve thorough surface cleaning and preparation.)

Q10. In painting and coating applications, what is the purpose of a primer?

1. To provide colour
2. To enhance gloss
3. To promote adhesion
4. To provide weather resistance

Answer: 3. To promote adhesion

(Explanation: A primer serves as a crucial preparatory layer in painting and coating applications, primarily designed to promote adhesion between the substrate (the surface being painted or coated) and the subsequent layers of paint or coating. Adhesion is essential for ensuring the longevity and durability of the coating system. Without proper adhesion, the paint or coating may peel, flake, or blister over time, compromising the protective properties of the coating. Primers typically contain adhesion-promoting agents that form a strong bond with both the substrate and the subsequent paint or coating layers. Additionally, primers may also provide corrosion resistance, filling of surface imperfections, and enhanced durability, depending on the specific formulation and intended application.)

Q11. In the context of raw materials for coatings, what is the purpose of a pigment?

1. To provide colour
2. To improve adhesion
3. To enhance corrosion resistance
4. To increase viscosity

Answer: 1. To provide colour

(Explanation: Pigments are finely ground solid particles added to coatings to impart colour, opacity, and other aesthetic properties. In the context of coatings, pigments serve primarily to provide colour, allowing manufacturers to achieve a wide range of hues and shades to meet diverse aesthetic requirements. Pigments come in various forms, including inorganic minerals, synthetic compounds, and organic dyes, each offering specific color characteristics and performance properties. Along with coloration, pigments may also contribute to opacity, hiding power (the ability to conceal the substrate), UV resistance, and weatherability of the coating. However, their primary function remains the provision of coloration, making pigments a fundamental component of coating formulations across industries such as automotive, architectural, and industrial coatings.)

Q12. During dimension inspection of a manufactured component, what is the tolerance zone?

1. The range of acceptable dimensions
2. It is a narrow zone between production and manufacturing.
3. The area where measurements are taken
4. The minimum acceptable surface finish

Answer: 1. The range of acceptable dimensions

(Explanation: In the context of dimension inspection, the tolerance zone refers to the acceptable range of dimensions specified for a manufactured component. It defines the permissible variation from the nominal or target dimension within which the component is considered acceptable for use. The tolerance zone includes both positive and negative deviations from the nominal dimension, allowing for variations in size and geometry that may occur during the manufacturing process. The dimensions of manufactured components are typically subject to dimensional tolerances, which are specified in engineering drawings or product specifications. These tolerances establish the allowable limits for dimensional variation to ensure proper fit, functionality, and interchangeability of parts in assemblies or systems. Dimensional inspection involves measuring the actual dimensions of a component and comparing them to the specified tolerances to verify compliance with quality standards and requirements.)

Q13. Which non-destructive testing (NDT) method is best suited for detecting surface cracks in metal components?

1. Ultrasonic testing
2. PAUT & TOFD
3. Liquid penetrant testing
4. Radiographic testing

Answer: 3. Liquid penetrant testing

(Explanation: Liquid penetrant testing, also known as dye penetrant testing, is a widely used non-destructive testing method for detecting surface-breaking defects, including cracks, in metal components. This method relies on the capillary action of a liquid penetrant to seep into surface discontinuities. First, a low-viscosity liquid penetrant is applied to the surface of the component, allowing it to infiltrate any surface cracks or voids through capillary action. After a specified dwell time, excess penetrant is removed from the surface, and a developer (typically a white, absorbent powder) is applied. The developer draws the penetrant out of the defects, causing them to become visible against the contrasting background. Liquid penetrant testing is highly sensitive and capable of detecting very fine cracks and defects on the surface of the material, making it an essential tool for quality control and inspection in various industries, including aerospace, automotive, and manufacturing.)

Q14. What is the purpose of a “Quality Hold Point” in construction projects and quality assurance plans (QAP)?

1. To mark the completion of a project phase
2. To obtain approval before proceeding to the next activity
3. To schedule inspections at random intervals
4. To document project progress for reporting purposes

Answer: 2. To obtain approval before proceeding to the next activity

(Explanation: A Quality Hold Point refers to a specific juncture in a project or process where the Contractor must obtain approval or a notice of no objection from the Engineer or Employer’s Representative before proceeding with the next activity. This ensures that critical quality control measures, such as inspections or testing, are completed and approved before advancing to the next phase of the project. The Quality Hold Point acts as a checkpoint to verify that the work meets specified quality standards and requirements, helping to prevent defects, errors, or non-compliance issues from progressing further in the project timeline. It ensures that necessary approvals are in place before crucial activities are undertaken, enhancing overall quality assurance and adherence to project specifications.)

Q15. What is the key difference between a Hold Point and a Witness Point in quality assurance and inspection processes?

1. A Hold Point requires mandatory verification before work can proceed, while a Witness Point involves optional inspection.
2. A Hold Point involves the review of methods or processes by an engineer, while a Witness Point requires approval from the municipality inspector.
3. A Hold Point signifies completion of a project phase, while a Witness Point marks the beginning of an activity.
4. A Hold Point necessitates approval by the engineer or consultant before work can continue, while a Witness Point allows activities to proceed without immediate approval.

Answer: 1. A Hold Point requires mandatory verification before work can proceed, while a Witness Point involves optional inspection.

(Explanation: In QAP, Hold Points and Witness Points serve as critical checkpoints to ensure that work adheres to specified standards and requirements. Hold Points represent stages within a process where work must halt until certain criteria are met and mandatory verification is completed. At these junctures, designated personnel, often engineers or quality assurance professionals, must thoroughly inspect, test, or review documentation to ensure that the work meets the necessary standards and specifications. Only upon fulfilment of the Hold Point requirements and obtaining approval can work proceed to the subsequent phase or activity.

In contrast, Witness Points also serve as checkpoints in the process, but they involve optional inspection or observation. While activities can progress at Witness Points without mandatory verification or approval, stakeholders such as inspectors, engineers, or clients have the option to observe the activities, perform inspections, or witness critical processes if they choose to do so. While their presence at Witness Points can provide additional assurance and oversight, their approval or verification is not required for work to continue.

The fundamental difference between Hold Points and Witness Points lies in the level of mandatory verification necessary before work can proceed. Hold Points necessitate mandatory verification and approval, ensuring that specific criteria are met before progressing to the next stage. On the other hand, Witness Points allow activities to proceed without immediate verification, but stakeholders have the option to observe or inspect if desired, providing an additional layer of oversight without halting progress.

In summary, Hold Points act as mandatory checkpoints where work must stop until verification and approval are obtained, ensuring compliance with standards, while Witness Points offer optional inspection opportunities, allowing activities to continue without immediate verification but providing stakeholders with the option to observe or inspect if they choose to do so, enhancing overall quality assurance and oversight within the process.

Q16. What is the primary distinction between a Quality Assurance Plan (QAP), an Inspection and Test Plan (ITP), and a Quality Control Plan (QCP) in construction and quality management processes?

1. A QAP outlines quality assurance procedures, an ITP focuses on inspection and testing protocols, while a QCP details quality control measures.
2. A QAP is focused on project specifications, an ITP details testing procedures, and a QCP ensures compliance with regulations.
3. A QAP defines quality objectives, an ITP specifies inspection points, and a QCP monitors project progress.
4. A QAP involves quality audits, an ITP includes quality checks, and a QCP manages quality documentation.

Answer: 1. A QAP outlines quality assurance procedures, an ITP focuses on inspection and testing protocols, while a QCP details quality control measures.

(Explanation: In construction and quality management processes, a Quality Assurance Plan (QAP) serves as the overarching document that outlines how to manage and ensure the best possible quality for the final product or service. It focuses on setting quality assurance procedures and standards to meet customer requirements and business objectives. On the other hand, an Inspection and Test Plan (ITP) is a detailed document that specifies when and where inspections and tests will be conducted during the project to verify compliance with standards. It provides a structured approach to monitoring quality at specific checkpoints. In contrast, a Quality Control Plan (QCP) is dedicated to detailing how quality will be monitored and controlled during work execution, emphasizing ongoing tracking, inspection, and adjustments to maintain quality standards throughout the project. The QCP focuses on managing quality in real-time to ensure that set standards are met consistently.

In simpler terms, a Quality Assurance Plan (QAP) guides us on the steps needed to ensure work is done correctly from the beginning. An Inspection and Test Plan (ITP) specifies when and where to inspect and test work at different stages. On the other hand, a Quality Control Plan (QCP) details how we will keep track of quality as work progresses, making sure that standards are met and maintained throughout the project. The QCP involves ongoing monitoring and adjustments to ensure that quality remains consistent and meets the required standards.)

Q17. In ultrasonic testing, what is the primary difference between an angle probe and a normal probe?

1. Angle probes are used for surface-breaking defects, while normal probes are for subsurface defects.
2. Angle probes are designed for oblique inspections at specific angles, while normal probes emit waves perpendicular to the surface.
3. Angle probes are suitable for high-frequency testing, while normal probes are better for low-frequency testing.
4. Angle probes require contact coupling, while normal probes can be used for immersion testing.

Answer: 2. Angle probes are designed for oblique inspections at specific angles, while normal probes emit waves perpendicular to the surface.

(Explanation: Angle probes in ultrasonic testing are specialized for oblique inspections at predetermined angles, such as 30°, 45° or 60°, allowing for effective examination of welds and other components. These probes are tailored for angled beam transmission to detect flaws in specific orientations. In contrast, normal probes emit ultrasonic waves perpendicular to the surface being tested, enabling direct and straightforward inspections without the need for angled beam adjustments. This distinction highlights the primary difference between angle probes, which are angled for specific inspections, and normal probes, which emit waves straight into the material for general surface testing.)

Q18. Which of the following activities are typically involved in the inspection of raw materials before they are used in manufacturing processes?

1. Visual inspection for defects
2. Chemical analysis for composition
3. Dimensional measurement for accuracy
4. Mechanical testing for strength properties
5. All of the above

Choose the correct combination of activities that are commonly part of raw material inspection:

Answer: 5. All of the above

(Explanation: Raw material inspection involves a comprehensive approach to ensure the quality and suitability of materials for manufacturing processes.

Visual inspection is essential for detecting any visible defects like surface imperfections, damage, or contamination.

Chemical analysis is conducted to determine the composition and purity of the raw materials, ensuring they meet required specifications.

Dimensional measurement is performed to verify the accuracy and consistency of the material’s size and shape.

Mechanical testing assesses the strength properties of the raw materials to ensure they meet the necessary mechanical requirements for the intended application.

By combining these activities, manufacturers can thoroughly evaluate raw materials to maintain product quality and performance standards.)

Q19. In the context of engineering and construction, what accurately describes the relationship between codes and standards?

1. Codes are legally enforceable regulations, while standards can become legally enforceable when adopted by regulatory authorities.
2. Codes and standards are interchangeable terms used to define industry best practices.
3. Codes focus on materials, while standards focus on construction methods.
4. Standards are specific to local regulations, while codes are international in scope.

Answer: 1. Codes are legally enforceable regulations, while standards can become legally enforceable when adopted by regulatory authorities.

(Explanation: Codes are legally enforceable regulations established by governmental authorities. They serve as mandatory guidelines governing various aspects of design, construction, and safety within the industry. Compliance with codes is obligatory, and failing to adhere to them can result in legal consequences. On the other hand, standards serve as guidelines developed through consensus among industry professionals, regulatory bodies, and stakeholders. While initially, standards may not be legally required, they can become legally enforceable when adopted by regulatory authorities. This adoption process transforms certain standards into legally binding regulations, making adherence mandatory rather than optional. For instance, standards developed by organizations like ASME (American Society of Mechanical Engineers) might be recognized and adopted by governmental bodies, thereby becoming mandatory requirements in certain jurisdictions. Therefore, the correct option (1) accurately describes the relationship between codes and standards, emphasizing the distinction between legally enforceable regulations (codes) and standards, which can attain legal status when adopted by regulatory authorities.)

Q20. Which of the following steel grades is commonly used for structural applications in construction?

1. AISI 304
2. ASTM A36
3. AISI 4140
4. ASTM A193

Answer: 2. ASTM A36

(Explanation: ASTM A36 is a widely used grade of structural steel in construction. It has excellent weldability and is suitable for a variety of structural applications, including buildings, bridges, and machinery. AISI 304 is a stainless steel grade commonly used in applications requiring corrosion resistance, while AISI 4140 is a high-strength alloy steel often used in engineering applications. ASTM A193 specifies alloy steel and stainless steel bolting materials for high-temperature or high-pressure service, not typically used for structural purposes. To learn more about SA36 steel.)

Q21. Which steel grade is specifically designed for use in extreme temperature environments, such as cryogenic applications?

1. AISI 316
2. ASTM A516
3. AISI 1018
4. ASTM A242

Answer: 2. ASTM A516

(Explanation: ASTM A516 is a steel grade designed for pressure vessel applications, particularly for moderate and lower temperature service. However, certain grades of ASTM A516, such as A516 Grade 70, are also suitable for cryogenic applications due to their excellent low-temperature toughness. AISI 316 is a stainless steel grade known for its corrosion resistance and is not specifically designed for cryogenic temperatures. AISI 1018 is a low carbon steel typically used in general engineering applications. ASTM A242 is a high-strength low-alloy structural steel used in building construction and other applications, but it is not specifically designed for extreme temperature environments like cryogenic conditions.)

Q22. Which of the following electrodes is most suitable for welding stainless steel to mild steel?

1. E7018
2. E6013
3. E309
4. E309L
5. Both 3 and 4

Answer: 5. Both 3 and 4

(Explanation: E309 is a filler metal used for welding stainless steel to mild steel. It has a higher ferrite content that can minimize weld dilution and prevent weld cracking.

E309L is a low-carbon version of E309 and is also used for welding stainless steel to mild steel. It has a lower carbon content and a higher silicon content than E309, making it more suitable for applications that have a risk of intergranular corrosion cracking.

Therefore, the correct answer is both E309 and E309L. Both electrodes are suitable for welding stainless steel to mild steel, but E309L is preferred for applications that have a risk of intergranular corrosion cracking.)

Q23. A welder deposited 10 thick weld during the performance qualification test (WQT). Up to what maximum thickness of weld metal is the welder qualified to weld as per ASME Section IX?

1. 8 mm
2. 12 mm
3. 15 mm
4. 20 mm

Answer: 4. 20 mm

(Explanation: As per Table QW-452.1(b) – ASME Section IX, Thickness of Weld Metal Qualified is “2t”

Where “t ” is thickness of the deposited weld metal in the coupon during the welder qualification (performance qualification) test. Hence, if the welder has deposited 10 mm thick weld during the test, he/she can weld upto a thickness of 20 mm (2t = 2X10 mm = 20 mm).

If a welder deposits weld metal of thickness 13 mm or more (with a minimum of three layers) then he/she qualifies for an unlimited thickness, but the maximum thickness which the welder can weld shall not be more than that specified in the WPS range. 

To read more about welder qualification test or performance qualification test, please click here.

Q24. A welder is qualified in the 3G position. In what welding positions can he perform welding, specifically for groove joints of plates as per ASME Section IX?

1. All Positions
2. Flat & Vertical
3. Flat, Vertical & Horizontal
4. Vertical Only

Answer: 2. Flat and Vertical

(Explanation: As per table QW-461.9 of ASME Section IX, A welder qualified with 3G position can weld flat and vertical position only in groove joints of plates.)

Q25. Which preheat temperature would be considered qualified, if a SMAW procedure qualification specifies a minimum preheat temperature of 120°C, but the PQR test coupon was welded with a minimum preheat temperature of 110°C, and all other PQR tests passed as per ASME Section IX?

1. 120°C
2. 110°C
3. 250°C
4. 160°C

Answer: 1. 120°C

(Explanation: As per Table QW 253, Paragraph 406.1: A decrease of more than 100°F (55°C) in the preheat temperature qualified will be considered as an essential variable.

It means, QW 406.1 allows the preheat temperature listed in the WPS to be decreased by up to 100°F (55°C) during the PQR test.

In other words, it permits reducing the listed preheat temperature on the WPS by up to 100°F (55°C) during the PQR test.

In the given scenario, the WPS lists a minimum preheat temperature of 120°C. During the PQR test, the preheat temperature was reduced to 110°C, which is a decrease of 10°C. This decrease is within the 100°F (55°C) limit allowed by QW 406.1.

Since all other PQR tests passed, and the preheat temperature decrease was within the allowed limit, the qualified WPS preheat temperature would be 120°C.)

Q26. In GTAW, what category of variable is the removal or inclusion of filler metal in a Welding Procedure Specification (WPS) as per ASME Section IX?

1. Essential Variable
2. Non-Essential Variable
3. Supplementary Essential Variable
4. Impact Variable

Answer: 1. Essential Variable

(Explanation: As per table QW-256, Paragraph QW-404.14: The deletion or addition of filler metal is an essential variable)

Q27. For SMAW, What type of variable is a change in F number from a WPS as per ASME Section IX?

1. Essential Variable
2. Non-Essential Variable
3. Supplementary Essential Variable
4. Impact Variable

Answer: 1. Essential Variable

(Explanation: As per table QW-253, Paragraph QW-404.4: A change from one F-number to any other F-Number is an essential variable)

Q28. What is the P-number of SA516 Gr.60?

1. P-number 2B
2. P-number 1A
3. P-number 4
4. P-number 1

Answer: 4. P-number 1

(Explanation: Refer Table QW/QB – 422: Both P-number and Group number of SA 516 Gr. 60 is 1)

Q29. What is the F-number of E6013?

1. F-number 1
2. F-number 1A
3. F-number 2
4. F-number 4

Answer: 3. F-number 2

(Explanation: Refer Table QW – 432: The F-number of E6013 is 2 )

Q30. What is the ‘A’ number when welding P No. 1 carbon steel to P No. 1 carbon steel using E7018 filler metal (SFA 5.1 classification)?

1. A-number 5
2. A-number 2
3. A-number 4
4. A-number 1

Answer: 4. A-number 1

(Explanation: Since, both P1 and F4 are carbon steel (mild steel), the resultant weld metal will also be mild steel. Now Refer Table QW – 442: The A-number for mild steel is 1, hence, option 4 i.e. A-number – 1 is the correct answer)

Q31. A welder is qualified with E7018 (without backing), can he weld with E6013 as per ASME Section IX?

1. Yes but with backing only
2. Yes, either with or without backing
3. No
4. None of these

Answer: 1. Yes but with backing only

(Explanation:  Step 1: Identify the F-numbers:

• Refer to Table QW-432 to find the F-numbers for E7018 and E6013.
• E7018 has an F-number of 4, and E6013 has an F-number of 2.

Step 2: Qualification Requirements: (www.weldingandndt.com)

• To determine if the welder is qualified to use E6013, refer to Article QW-433 (Alternate F-Numbers for Welder Performance Qualification).
• Article QW-433 Guidelines: According to QW-433, a welder qualified with an F-number 4 electrode (such as E7018) without backing is qualified to weld with an F-number 2 electrode (such as E6013) only with backing.

Additional Note: ASME Section IX specifies that a double “V” groove is also considered as welding with backing.

Therefore, a welder qualified with E7018 without backing can weld with E6013, but only if backing is used.)

Q32: Which welding position requires the test piece to be held at a 45-degree angle?

1. 2G
2. 2F
3. 3G
4. 3F
5. 1F

Answer: 5. 1F

(Explanation: According to QW-132.1, the 1F welding position involves a pipe positioned at a 45-degree angle to the horizontal, which is rotated during welding so that the weld metal is applied from above. At the point of deposition, the weld axis is horizontal and the throat is vertical. To learn more about welding test positions and see the photograph of the welding test positions, please visit: https://www.weldingandndt.com/welding-positions/)

Q33. What is the minimum diameter a welder qualifies for when tested on a NPS 2 pipe using GTAW according to ASME Section IX?

1. 0.5 inches (12.7 mm)
2. 0.75 inches (19.1 mm)
3. 1 inch (25 mm)
4. 1.5 inches (38.1 mm)

Answer:3. 1 inch (25 mm)

(Explanation: The welder has been tested on a NPS 2 pipe. For a  NPS 2 pipe, the outer diameter (OD) is 2.375 inches (60.3 mm). (To find out the OD and thickness of a pipe according to NPS, please refer to ASME B31.10)

According to ASME Section IX, Table QW-452.3, if a welder is tested on a pipe with an OD between 1 inch (25 mm) and 2.875 inches (73 mm), the minimum qualified diameter is 1 inch (25 mm). Therefore, the correct answer is 1 inch. (25 mm). A simplified for of Table 452.3 is given below.)

To learn more about welder performance qualification test, Please read this article: https://www.weldingandndt.com/welder-performance-test/)

Q34. If a welder is qualified on a NPS 4 pipe test coupon welded with SMAW, what is the qualified diameter (OD) range?

1. 73 mm to Unlimited
2. NPS 2-1/2 to Unlimited
3. DN 65 to Unlimited
4. All of the above

Answer: 4. All of the above

(Explanation: The welder has been tested on a NPS 4 pipe. For a NPS 4 pipe, the outer diameter (OD) is 4.500 inches or 114.3 mm. 

According to ASME Section IX, Table QW-452.3, if a welder is tested on a pipe with an OD greater than 73 mm ( 2-7/8 inches), the qualified diameter (OD) range is 73 mm (2-7/8 inches) to Unlimited. Note that 2-7/8 in. (73 mm) O.D. is the equivalent of NPS 2-1/2 (DN 65), as mentioned in the general notes of Table QW-452.3. Therefore, all the options are correct.

Q35: What information should be documented in a Welder Performance Qualification (WPQ) test according to ASME Section IX?

1. All essential and non-essential variables
2. All essential, non-essential, and supplementary essential variables (if required)
3. All parameters requested by the inspector during welding including the type of test and test results, and the ranges qualified
4. Essential variables, the type of test and test results, and the ranges qualified

Answer: 4. Essential variables, the type of test and test results, and the ranges qualified

(Explanation: Please refer QW-301.4 (Record of Tests): The Welder Performance Qualification (WPQ) test record must include the essential variables (refer to QW-350), the type of test conducted, the test results, and the qualified ranges as specified in QW-452 for each welder. Following formats can be used for the WPQ documentation.

Form QW-484A for Welder Performance Qualifications & Form QW-484A for Welding Operator Performance Qualifications)

Q36. When a welder needs to be certified through radiographic examination, what is the minimum length required for the test coupon used in the qualification process as per ASME section IX?

1. 4 inches (100 mm)
2. 6 inches (150 mm)
3. 8 inches (200 mm)
4. 12 inches (300 mm)

Answer: 2. 6 inches (150 mm)

(Explanation: As per QW-302.2 of ASME Section IX, When a welder is required to be qualified by radiographic examination, the minimum length of the test coupon must be 6 inches (150 mm. This length must encompass the entire circumference of the weld for pipes. In cases where the diameter of the pipe is small, multiple test coupons may be used, but the total number should not exceed four consecutively made test coupons. The examination technique and acceptance criteria shall be in accordance with QW-191.)

Q37. A Procedure Qualification test conducted using a groove weld on a plate that is 2 inches (50 mm) thick (welding process: SAW), the welder filled the entire groove with allowable reinforcement. what is the qualified WPS thickness range as per ASME Sec IX?

1. 5 mm to 100 mm (3/16 inch to 4 inches)
2. 10 mm to 50 mm (3/8 inch to 2 inches)
3. 50 mm to 100 mm (2 inches to 4 inches)
4. 5 mm to 200 mm (3/16 inch to 8 inches)

Answer: 4. 5 mm to 200 mm (3/16 inch to 8 inches)

(Explanation: According to QW-451.1 in ASME Section IX, the thickness range that can be qualified for a Welding Procedure Specification (WPS) is from 5 mm to 200 mm, which is equivalent to 3/16 inch to 8 inches.

Important Note: Please check Note 3 located below the table QW-451.1 in the standard. This note states that this thickness range is only applicable for Shielded Metal Arc Welding (SMAW), Submerged Arc Welding (SAW), Gas Tungsten Arc Welding (GTAW), and Gas Metal Arc Welding (GMAW). Since the welding process mentioned in our question is Submerged Arc Welding (SAW), we can use this thickness range for our qualifications.)

Q38. As per ASME Section IX, what is the maximum size of a fillet weld that can be performed using a Welding Procedure Specification (WPS) qualified on a fillet joint with a base metal thickness (T) of 3/8 inch?

1. 1.1T
2. All fillet sizes
3. 2T
4. 1.1 T

Answer: 2. All fillet sizes

(Explanation: As per Table QW-451.3, any size of fillet weld can be applied to all base metal thicknesses and diameters, provided that a Welding Procedure Specification (WPS) is qualified on a fillet joint in accordance with Figure QW-462.4(a).

Q39. What does the ’70’ refer to in a E7018 electrode?

1. Tensile strength: 70 ksi (minimum)
2. Yield strength: 70 ksi (minimum)
3. Tensile strength 70 Mpa (minimum)
4. Tensile strength: 70 ksi (maximum)

Answer: 1. Tensile strength: 70 ksi (minimum)

(Explanation: The “70” in a SMAW electrode refers to the minimum tensile strength of the deposited weld metal. This is expressed in ksi (thousand pounds per square inch). Thus, the correct interpretation of the ’70’ in E7018 is that it refers to the minimum tensile strength of 70 ksi. This can be found in ASME section II Part C)

Q40. What is the minimum distance from the surface to be examined that must be cleaned before conducting a magnetic particle test, as per ASME Section V?

1. 0.5 inches (12.5 mm)
2. 1 inch (25 mm)
3. 2 inches (50 mm)
4. 3 inches (75 mm)

Answer: 2. 1 inch or 25 mm

(Explanation: According to ASME Section V, Article 7, T-741.1 (b), before conducting a magnetic particle inspection, The surface and all adjacent areas within at least 1 inch (25 mm) must be free from various contaminants. These include dirt, grease, lint, scale, welding flux, spatter, oil, and any other extraneous materials that could interfere with the examination process.)

Q41. An elongated slag of 5 mm is observed on a long seam weld joint of a pressure vessel with a plate thickness of 12 mm. According to ASME Section VIII Division 1, can this be accepted?

1. Yes, because the slag is less than 6 mm
2. Slag is not acceptable on a long seam joint
3. Yes because slag is a non critical defect
4. No, because the slag exceeds 4 mm

Answer: 1. Yes, because the slag inclusion is less than 6 mm

Explanation: According to ASME Section VIII Division 1, for a plate thickness upto 19 mm, any elongated indication (such as slag) is considered unacceptable if its length exceeds 6 mm. Since the observed slag inclusion is 5 mm, it falls within the acceptable limit and can be accepted under this construction code. To learn more about the acceptance criteria.)

Q42. What is a “defect” in welding?

1. A minor flaw that can be accepted from the application point of view
2. A discontinuity that meets acceptance criteria
3. A discontinuity that doesn’t meet the acceptance criteria
4. An imperfection that passes inspection

Answer: 3. A discontinuity that doesn’t meet the acceptance criteria

(Explanation: A “defect” is specifically defined as a discontinuity or a series of discontinuities that make a part or product unable to meet the minimum applicable acceptance standards or specifications. This means that the presence of such defects renders the part or product unacceptable for use, leading to its rejection.)

Q43. What is the primary difference between Quality Assurance (QA) and Quality Control (QC) from a mechanical engineering perspective?

1. QA focuses on inspecting finished products after they are made, while QC involves creating quality standards.
2. QA is about establishing processes and procedures to prevent defects, while QC is about detecting and correcting defects through inspection and testing.
3. QA is concerned with the final product only, whereas QC deals with the entire manufacturing process.
4. QA and QC are the same and can be used interchangeably in all contexts.

Answer: 2. QA is about establishing processes and procedures to prevent defects, while QC is about detecting and correcting defects through inspection and testing.

(Explanation: Quality Assurance (QA) is about ensuring that the processes used to create products are effective and efficient, focusing on planning and systematic activities to prevent defects before they occur. In contrast, Quality Control (QC) involves the inspection and testing of products to identify and fix defects after they have occurred. Simply put, QA is proactive and process-oriented, while QC is reactive and product-oriented.)

Q44. What is the main advantage of using pre-fabricated components in construction?

1. Reduced material costs
2. Improved on-site safety and faster construction times
3. Enhanced aesthetic appearance
4. Increased need for skilled labour

Correct Answer: 2. Improved on-site safety and faster construction times.

(Explanation: The primary advantage of using pre-fabricated components in construction is that they are manufactured off-site (fabrication shops) in controlled environments, which allows for quicker assembly on-site. This significantly reduces construction times, enabling projects to be completed more efficiently. Additionally, having fewer workers on-site at any given time improves safety by minimizing the risk of accidents. The controlled factory setting also enhances quality control, leading to fewer mistakes and less rework. While reduced material costs and aesthetic improvements can be benefits of prefabrication, the most significant advantages are related to safety and speed of construction.)

Q45. What are the key differences between hydraulic and pneumatic systems?

1. Hydraulic systems use liquids, while pneumatic systems use gases
2. Hydraulic systems are generally faster than pneumatic systems
3. Pneumatic systems can handle higher pressures than hydraulic systems
4. Both systems operate on the same principles and components

(Explanation: The primary difference between hydraulic and pneumatic systems is the medium they use: hydraulic systems utilize liquids (usually oil) to transmit power, while pneumatic systems use compressed gases (typically air). This fundamental distinction affects their applications, pressure capabilities, and overall performance. Hydraulic systems are often used for heavy lifting and precise control, while pneumatic systems are preferred for lighter tasks and faster operation.)

Q46. How does a heat exchanger work?

1. It converts electrical energy into thermal energy
2. It transfers heat from one fluid to another without mixing them
3. It cools fluids by exposing them to ambient air
4. It generates heat through chemical reactions

(Explanation: A heat exchanger is a device that transfers heat between two or more fluids without allowing them to mix. It works on the principle of heat transfer through conduction, convection, or radiation. Common types include shell-and-tube, plate, double pipe, finned tube, and air-cooled exchangers. Shell-and-tube exchangers consist of a shell with tubes inside, allowing fluids to flow through the tubes and shell, facilitating efficient heat transfer. Plate exchangers use stacked plates with thin surfaces to transfer heat between fluids. These devices are crucial in heating, cooling, and energy recovery applications across industries like HVAC, power generation, and chemical processing.)

Q47. Which nondestructive testing method uses sound waves to find internal flaws in welds?

1. Radiographic testing
2. Ultrasonic testing
3. Magnetic particle testing
4. Visual inspection

(Explanation: Ultrasonic testing is the go-to method for spotting internal flaws in welds by using sound waves. It works by sending high-frequency sound waves into the material, and when these waves hit a flaw, they bounce back, letting inspectors know there’s an issue. While radiographic testing uses X-rays to check for defects, magnetic particle testing looks for surface cracks in ferromagnetic materials, and visual inspection is all about checking the surface with the naked eye, ultrasonic testing really stands out for its ability to dive deep and catch those hidden problems without causing any damage. So, if you want to get a good look at what’s going on inside a weld, ultrasonic testing is where it’s at!)

Q48. Which law of thermodynamics is like the golden rule of energy, stating that energy can’t be created or destroyed, only changed from one form to another?

1. The Law of Conservation of Energy
2. The Law of Entropy
3. The Law of Thermodynamics Zero
4. The Law of Increasing Disorder

Explanation: The Law of Conservation of Energy is the correct answer. This fundamental law of thermodynamics states that energy cannot be created or destroyed, only transferred or converted from one form to another. It’s a cornerstone principle in physics and engineering.

Q49. Cracks caused by a combination of tensile stress and corrosion are called:

1. Cycling cracks
2. Critical cracks
3. Fatigue cracks
4. Stress corrosion cracks

(Explanation: The stress corrosion cracks cracks develop due to the simultaneous action of tensile stress and a corrosive environment, leading to material degradation. Other options are less suitable: cycling cracks is not a standard term, critical cracks do not specifically refer to this mechanism, and fatigue cracks result from cyclic stresses rather than corrosion.)

Q50. Which electrode is commonly used for welding mild steel in general fabrication?

1. E6010
2. E6013
3. E7018
4. E7024

(Explanation: E6013 is most widely used for mild steel fabrication because it provides smooth arc, less spatter, easy slag removal, and good appearance.)

Q51. The “70” in E7018 electrode indicates:

1. Minimum tensile strength of 70 ksi (490 MPa)
2. Yield strength of 70 ksi
3. 70% ductility
4. 70% efficiency

(Explanation: The first two digits of AWS electrode classification indicate the minimum tensile strength of the weld deposit in ksi (1 ksi = 1000 psi). E7018 weld metal has ≥ 70 ksi tensile strength.)

Q52. Which electrode is best suited for deep penetration welding of mild steel pipelines?

1. E6010
2. E6013
3. E7018
4. E7024

(Explanation: E6010 electrodes have a cellulose coating that gives deep penetration, strong arc force, and fast-freezing slag, making them suitable for pipeline and root-pass welding.)

Q53. Which filler metal is commonly used for GTAW (TIG) welding of aluminium?

1. ER4043
2. ER308L
3. E6013
4. ER70S-6

(Explanation: ER4043 is a common aluminium-silicon alloy filler used for welding aluminium alloys, offering good fluidity and crack resistance. To learn more about Aluminium and Aluminium alloy.)

Q54. Why is a heat number important in incoming inspection?

1. Identifies the supplier of the material
2. Links the material to its Mill Test Certificate (MTC)
3. Shows the production shift during which material was made
4. Indicates the steelmaking method used

(Explanation: A heat number is a unique code stamped on the material which directly connects it to its Mill Test Certificate – MTC. This ensures traceability)

Q55. Why is Ultrasonic Testing (UT) done on plates during incoming inspection?

1. To check for lamination defects
2. To measure the tensile strength of the plate
3. To verify impact toughness of the plate
4. To confirm weldability of the plate

(Explanation: UT is used to detect internal flaws like laminations inside the plate which cannot be seen on the surface. Laminations are a flat, layer-like internal defect in a metal plate formed during rolling, caused by trapped gas, inclusions, or weak bonding between layers.)

Q56. Why are laminations unacceptable in plates?

1. They increase the strength of the material
2. They cause lamellar tearing and weaken welded joints
3. They improve strength
4. They can be removed by grinding then accepted

(Explanation: Laminations are internal defects that run parallel to the plate surface. During welding, shrinkage and through-thickness stresses open these laminations, leading to lamellar tearing and weaken the welded joints)

Q57. Why is a heat number important in incoming inspection?

1. Identifies manufacturer
2. Links material to test certificate
3. Shows batch size
4. Indicates steelmaking process

(Explanation: Heat number ensures traceability between the physical product and its test results on the MTC.)

Q58. Which of the following electrodes is most suitable for welding mild steel to cast iron?

1. E7018
2. E6013
3. Nickel-based electrode (ENiFe-CI)
4. E309L
5. Both 3 and 4

(Explanation: Nickel-based electrodes provide a ductile weld deposit and reduce cracking tendency when joining cast iron to steel. E7018/E6013 are unsuitable because they don’t handle dissimilar metal dilution.)

Q59. Which type of stainless steel is not hardenable by heat treatment?

1. Martensitic
2. Ferritic
3. Austenitic
4. Duplex
5. Both 2 and 3

(Explanation: Austenitic stainless steels like 304 and 316 cannot be hardened by heat treatment; they are hardened only by cold working. Martensitic grades, on the other hand, are hardenable by heat treatment.)

Q60. Which NDT method is most effective for detecting surface cracks on a non-magnetic stainless steel?

1. MPI
2. LPI
3. UT
4. RT
5. Both 1 and 2

(Explanation: Magnetic particle testing – MPI works only on ferromagnetic materials. For non-magnetic stainless steels, liquid penetrant testing – LPI is the most suitable for surface crack detection.)

Q61. You are performing MT (Magnetic Particle Test) on a HAZ of a low-alloy steel weld in a power-plant application. The surface cleaning indicates residual mill scale remains (~0.2 mm thick). The quality engineer should:

1. Proceed – as long as indications are not found the test is valid.
2. Proceed – mill scale doesn’t matter for MT.
3. Stop and instruct to remove mill scale fully before MT.
4. Switch to UT instead of MT because of the surface condition.

(Explanation: The quality engineer must stop and instruct that all residual mill scale be fully removed before performing MT on the HAZ of a weld. Magnetic Particle Testing requires a clean, bare metal surface because mill scale, rust, paint, and other residues inhibit proper magnetic particle movement and mask indications, resulting in unreliable test results. Proceeding with mill scale present could cause defects to go undetected.)

Q62. During welding of a boiler tube joint, excessive porosity observed in the root pass. The base metal is SA-210 Gr A1, and electrode used is E7018. The most likely cause is:

1. Incorrect electrode type.
2. Low heat input causing lack of fusion.
3. Moisture in electrode or improper baking.
4. Excessive interpass temperature.

(Explanation: E7018 is a low-hydrogen electrode and absorbs moisture if not baked or stored properly. This moisture decomposes during arc formation and produces hydrogen gas, causing porosity in the weld metal. Proper baking/holding at recommended temperature avoids such gas entrapment.)

Q63. During RT of a butt weld, the radiograph shows elongated slag inclusions parallel to the weld axis. The most probable cause is:

1. Incorrect exposure time.
2. Inadequate cleaning between passes.
3. Excessive root gap.
4. Overlapping of films during exposure.

(Explanation: Slag inclusions occur when slag from a previous pass is not fully removed before depositing the next layer. They appear as elongated or linear indications along the weld axis in RT films, indicating poor interpass cleaning.)

Q64. In RT, cluster of fine dark spots indicates:

1. Slag inclusion
2. Lack of fusion.
3. Porosity
4. Tungsten inclusion

(Explanation: Porosity appears as rounded or nearly spherical dark indications on radiographs, typically gas-shaped, and may be seen scattered randomly or clustered together within the weld zone.)

Q65. You are reviewing a radiograph (RT) of a 25mm thick double-V butt weld and notice a sharp, dark, straight line running precisely down the center of the weld. However, when the UT technician scans the exact same location using a standard 60 degree shear wave probe from the plate surface, they report zero indications exceeding the code rejection threshold. What is the most likely structural reason for this discrepancy?

1. The flaw is a tight, vertical centerline lack of fusion that reflects the UT beam away from the probe.
2. The RT film was outdated, creating a localized processing artifact.
3. The flaw is high-density tungsten inclusion, which UT cannot detect.
4. The UT technician forgot to use couplant on that specific segment.

(Explanation: A tight, vertical centerline lack of fusion allows more X-rays to pass straight through, creating a sharp, dark line on the film. Conversely, conventional Ultrasonic Testing (UT) relies on acoustic reflection. When a 60 degree shear wave hits that same perfectly vertical flaw, the sound bounces forward and away from the probe like light hitting a tilted mirror. Because no sound energy returns to the transducer, the UT machine shows a flat baseline, completely missing a defect that RT caught perfectly.)

Q66. In the AWS classification for carbon steel SMAW electrodes (e.g., E7018), what does the third digit (1) represent?

1. The minimum tensile strength of the weld metal
2. The recommended welding position
3. The type of coating and current characteristics
4. The chemical composition of the core wire

(Explanation:

• E: Stands for Electrode (specifically for Shielded Metal Arc Welding).

• 70 (first two digit): Represents the Minimum Tensile Strength of the weld metal in kilo-pounds per square inch (ksi). In this case, 70,000 psi.

• 1 (Third Digit): Indicates the Welding Position.

  • 1 means All Positions (Flat, Horizontal, Vertical, and Overhead).

  • 2 means Flat and Horizontal fillet positions only.

  • 4 indicates Flat, Horizontal, Overhead, and Vertical-down positions.

• 18 (Last two Digit): Indicates the Coating Type (Iron powder, low hydrogen) and the Current/Polarity it can operate on (AC or DCEP).

1. To outline the qualifications of the welder
2. To specify the welding process and variables
3. To determine the cost of the welding project
4. To schedule welding activities

(Explanation: A Welding Procedure Specification (WPS) is a document that provides the details of the variables (parameters) such as joint design, base metal details, filler metal/electrode details, preheat, post heat, PWHT details, current, voltage, heat input details etc. to the welders or welding operators to create welds as per the requirements. The variables in the WPS are categorized as Essential Variables, Non-Essential Variables & Supplementary Essential Variables)

Q2. What is the difference between essential and non-essential variables in welding?

1. Essential variables are considered to affect the mechanical properties of the weld (other than toughness properties), while non-essential variables do not.
2. Essential variables are mandatory, while non-essential variables are optional.
3. Essential variables are easily adjustable, while non-essential variables are fixed.
4. Essential variables are related to safety, while non-essential variables focus on aesthetics.

(Explanation: Essential variables in welding is considered to affect the mechanical properties (other than toughness properties) of the joint. Therefore, any changes in the essential variables necessitate the re-qualification of the Welding Procedure Specification (WPS). This ensures that the welding process maintains its integrity and meets the required standards for strength, ductility, and other mechanical characteristics of the welded joint.)

Q3. What distinguishes an essential variable from a supplementary essential variable in a Welding Procedure Specification (WPS)?

1. Essential variables impact the mechanical properties of the joint, while supplementary essential variables affect toughness properties.
2. Essential variables are optional, whereas supplementary essential variables are mandatory.
3. Essential variables focus on aesthetics, while supplementary essential variables ensure safety.
4. Essential variables require re-qualification of the WPS, while supplementary essential variables do not.

(Explanation: Essential variables are considered to affect the mechanical properties of the weld and necessitate re-qualification of the WPS, if changed. On the other hand, supplementary essential variables primarily affect the toughness properties of the joint. Hence, If a supplementary essential variable is changed, it will affect the toughness properties of the joint, heat-affected zone, or base material (toughness property is also a mechanical property). Hence, Supplementary essential variables become additional essential variables when referencing code, standard, or specification requires toughness testing for procedure qualification. Hence, the WPS must be re-qualified. In other words we can say that the supplementary variables become just as important as essential variables when rules or standards require toughness testing for the welding process to be approved.)

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Q4. What does the term “preheating” refer to in welding?

1. Heating the base metal before welding
2. Cooling the welded joint after completion
3. Applying heat to the filler material
4. Inspecting the weld visually

(Explanation: Preheating in welding refers to the process of heating the base metal before starting the welding. This is done to raise the temperature of the base metal to a level that primarily retards or slows down the cooling rate of the molten weld pool. Preheating can also help to reduce the risk of thermal stresses and distortion during the welding process.)

Q5. Which of the below mentioned non-destructive testing method can be used to detect surface-breaking defects in welds which are not visible to the naked eye?

1. Iron sulphide testing
2. Ultrasonic testing
3. Magnetic particle testing
4. Visual inspection

(Explanation: Magnetic particle testing (MT) is a non-destructive testing method used to detect surface as well as sub-surface defects in welds. It involves applying a magnetic field to the weld, which causes any defects to become visible as magnetic particles adhere to the defects.)

Q6. What is the purpose of post-weld heat treatment (PWHT)?

1. To cool down the welded joint gradually
2. To relieve residual stresses and improve toughness
3. To accelerate the cooling process of the weld
4. To prevent oxidation of the weld metal

(Explanation: Post-weld heat treatment (PWHT) is a process used to improve the mechanical properties of a welded joint. It involves heating the welded joint to a specific temperature and holding it at that temperature for a certain period. PWHT helps to relieve residual stresses that can cause cracking and other defects in the weld. It also improves the toughness of the weld, making it more resistant to impact and fatigue.)

Q7. Which welding process uses a consumable electrode that also acts as a filler material?

1. Gas Metal Arc Welding (GMAW)
2. Shielded Metal Arc Welding (SMAW)
3. Flux-Cored Arc Welding (FCAW)
4. Gas Tungsten Arc Welding (GTAW)
5. 1, 2 & 3

(Explanation: In all three cases i.e. GMAW, SMAW, & FCAW, the electrodes used in Gas Metal Arc Welding (GMAW), Flux-Cored Arc Welding (FCAW), and Shielded Metal Arc Welding (SMAW) are designed to act as filler materials. The main difference lies in the type of electrode and shielding gas used in each process:

• GMAW uses a continuous wire electrode that also acts as a filler wire.
• FCAW uses a tubular wire filled with flux at the core.
• SMAW uses a coated electrode that melts and forms a molten pool, which is then solidified to create a strong joint.

In summary, all three welding processes use electrodes that act as filler materials, but they differ in the type of electrode and shielding gas used..)

Q8. What is the difference between PWHT and post heat in welding?

1. The need for temperature monitoring
2. The timing of the heat application
3. The type of joint configuration
4. The impact on visual appearance

(Explanation: Post-Weld Heat Treatment (PWHT) involves heat treatment applied after welding to relieve residual stresses and enhance mechanical properties. On the other hand, post-heat refers to heat applied immediately after a specific welding pass to control cooling rates and prevent cracking. Understanding the timing of heat application distinguishes these two practices in welding.)

Q9. What is the significance of interpass temperature control in multi-pass welding?

1. It ensures uniform heat distribution throughout the weld
2. It prevents excessive heat input and distortion
3. It minimizes the risk of hydrogen-induced cracking
4. It improves the fusion between weld passes

(Explanation: Controlling interpass temperature prevents hydrogen from accumulating in the weld, reducing the likelihood of cracks. By maintaining specific temperature ranges between subsequent weld passes, the cooling rate is controlled, reducing the potential for hydrogen absorption and cracking in the weld metal.)

Q10. What is the purpose of using a back gouging process in welding?

1. To remove surface contaminants before welding
2. To create a beveled edge for welding preparation
3. To inspect internal defects in welded joints
4. To enhance post-weld heat treatment effectiveness

(Explanation: The back gouging process in welding involves removing material from the root side of a weld joint to create a beveled or grooved edge. This preparation is done to facilitate proper welding penetration and fusion when joining the two pieces of metal. It allows for better access to the joint and ensures the welding from root side could be done in a proper way.)

Q11. What is the purpose of visual inspection of weld joints?

1. To measure the hardness of the weld
2. To assess the weld’s mechanical properties
3. To visually check for surface defects and discontinuities
4. To determine the chemical composition of the weld

(Explanation: Visual inspection of weld joints involves visually examining the welded joint to identify surface defects and discontinuities such as cracks, porosity, undercut, incomplete penetration (if joint is accessible from the root side), and other visible irregularities. While it provides valuable information about the overall quality and appearance of the weld, it does not measure hardness, assess mechanical properties, or determine the chemical composition of the weld.)

Q12. What is the purpose of a Charpy V-notch test?

1. To measure the hardness of the weld
2. To assess the impact toughness of the weld
3. To determine the tensile strength of the weld
4. To evaluate the ductility of the weld

(Explanation: The Charpy V-notch test evaluates how well a weld can absorb energy under impact, indicating its resistance to sudden loads or shocks. This test helps assess the weld’s ability to withstand sudden stress without fracturing, providing crucial insights into its toughness and reliability.)

Q13. What is the purpose of a Dye Penetrant Test in welding inspection?

1. To measure the hardness of the weld
2. To detect surface-breaking defects in the weld
3. To assess the impact toughness of the weld
4. To determine the chemical composition of the weld

(Explanation: A Dye Penetrant Test is used to identify surface defects like cracks, porosity, or laps that are not visible to the naked eye by applying a colored dye that penetrates these imperfections, making them visible for inspection.)

Q14. What does the term “Welding Position” refer to in welding procedures?

1. The orientation of the welder during welding
2. The location where welding is performed
3. Orientation and configuration of the joint being welded
4. The angle at which the electrode is held during welding

(Explanation: Welding Position describes the specific orientation and configuration of the joint being welded, such as flat, horizontal, vertical, or overhead, which influences welding technique and parameters.)

Q15. What is the primary function of a Radiography Test (RT) in welding inspection?

1. To measure the thickness of the weld
2. To assess the hardness of the weld
3. To detect internal defects in the weld
4. To determine the tensile strength of the weld

(Explanation: Radiography Testing involves using X-rays or gamma rays to examine internal weld structures for defects like cracks, voids, or lack of fusion etc. that may not be visible externally.)

Q16. What is the primary purpose that distinguishes Post-Weld Heat Treatment (PWHT) from post-heat in welding?

1. Improving visual appearance
2. Controlling cooling rates during welding
3. Relieving residual stresses and enhancing mechanical properties
4. Minimizing the risk of thermal distortion

(Explanation: While both PWHT and post-heat involve the application of heat in welding, PWHT is specifically designed to relieve residual stresses and improve mechanical properties, setting it apart from post-heat, which focuses on controlling cooling rates during the welding process.)

Q17. What is the purpose of conducting a Positive Material Identification (PMI) test on incoming materials?

1. To measure the hardness of the material
2. To verify the chemical composition of the material
3. To assess the tensile strength of the material
4. To evaluate the impact toughness of the material

(Explanation: Positive Material Identification (PMI) inspection is primarily used to analyze and identify the material grade and alloy composition. The fundamental principle of PMI involves utilizing analytical techniques like X-ray fluorescence (XRF) or optical emission spectroscopy (OES) to determine the elemental composition of materials without causing damage or alteration. This process is crucial for verifying the chemical composition of metals and alloys quickly and non-destructively, ensuring quality and safety control in various industries.)

Q18. Why is it important to conduct a Visual Inspection on raw materials before welding?

1. To determine the mechanical properties of the materials
2. To identify surface defects or contaminants
3. To measure the thickness of the materials
4. To assess the hardness of the materials

(Explanation: Visual inspections help detect any visible defects, such as cracks, rust, or foreign materials, that could compromise weld quality if not addressed before welding.)

Q19. What does a Material Test Certificate (MTC) provide information about?

1. Welding procedures used during fabrication
2. Chemical composition and mechanical properties of materials
3. Welder qualifications for specific projects
4. Non-Destructive Testing (NDT) results on welded joints

(Explanation: MTCs provide essential information about raw materials, including their chemical composition, mechanical properties, and compliance with industry standards.)

Q20. What is the primary purpose of conducting Ultrasonic Testing (UT) on incoming materials?

1. To measure the thickness of the materials
2. To detect internal defects in the materials
3. To assess the hardness of the materials
4. To determine the chemical composition of the materials

(Explanation: UT is used to identify internal flaws like cracks or voids within material)

Q21. What is the primary objective of conducting a Bend Test on incoming raw materials?

1. Assessing material hardness and wear resistance
2. Evaluating material corrosion resistance capabilities
3. Determining material ductility
4. Identifying internal defects like cracks in raw materials

(Explanation: Bend Tests help assess how well a material can deform without breaking, indicating its ductility)

Q22. What is the primary purpose of Raw Materials Inspection in Quality Control?

1. To check the color of materials
2. To ensure materials meet specified quality standards
3. To count the quantity of materials
4. To verify the weight of materials

(Explanation: Raw Materials Inspection aims to assess whether incoming materials conform to predetermined quality criteria, ensuring that they meet the required standards for production.)

Q23. What does MTC stand for in the context of quality control?

1. Material Testing Certificate
2. Manufacturing Technical Checklist
3. Material Traceability Code
4. Material Tolerance Criteria

(Explanation: MTC, or Material Testing Certificate, is a crucial document providing information on the testing and compliance of materials with applicable standards.)

Q24. Which of the following is NOT a common incoming material inspection parameter?

1. Dimensional accuracy
2. Chemical composition
3. Material hardness
4. Employee attendance records

(Explanation: Incoming material inspection typically focuses on physical and chemical properties rather than personnel-related aspects.)

Q25. What is the significance of Material Traceability in Quality Control?

1. It ensures materials are visible in the warehouse
2. It helps track materials throughout the production process
3. It verifies the weight of materials
4. It counts the number of incoming materials

(Explanation: Material traceability is crucial for monitoring and tracing materials from their arrival through various production stages, ensuring quality and accountability.)

Q26. What role does a Third-Party Inspector play in the QC process?

1. Conducts internal audits
2. Represents the manufacturing company
3. Provides an unbiased assessment
4. Handles employee relations

(Explanation: A Third-Party Inspector offers an impartial evaluation of products or processes, ensuring objectivity in quality control assessments.)

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Q27. What does the material specification SA516 Gr 60 refer to?

1. A type of stainless steel alloy
2. A specific grade of carbon steel for pressure vessel applications
3. An aluminum alloy commonly used in structural applications
4. A high-strength titanium alloy

(Explanation: SA516 Gr 60 is a carbon steel grade specifically designed for pressure vessel applications due to its excellent weldability and toughness properties, making it ideal for withstanding high-pressure environments.)

Q28. How do SS304 and SS304L differ in terms of carbon content?

1. SS304 is magnetic, while SS304L is non-magnetic
2. SS304 has a higher carbon content than SS304L
3. SS304L is more resistant to corrosion than SS304
4. SS304 has a lower chromium content compared to SS304L

(Explanation: The main difference between SS304 and SS304L lies in their carbon content, with SS304 having a higher carbon content than SS304L, impacting their respective properties and applications.)

Q29. Why is SA516 Gr 60 commonly used in pressure vessel fabrication?

1. Due to its high resistance to corrosion
2. Because of its excellent weldability and toughness properties
3. For its lightweight characteristics
4. For its high thermal conductivity

(Explanation: SA516 Gr 60 is favored in pressure vessel fabrication for its exceptional weldability and toughness, ensuring reliable performance under high-pressure conditions.)

Q30. What advantage does SS304L offer over SS304?

1. Higher strength and hardness
2. Improved resistance to intergranular corrosion
3. Greater ductility and toughness
4. Enhanced thermal conductivity

(Explanation: SS304L provides enhanced resistance to intergranular corrosion compared to SS304, making it suitable for applications where corrosion resistance is critical.)

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Q31. What specific elements are controlled in the chemical composition of SA516 Gr 60 to meet pressure vessel requirements?

1. Carbon, manganese, and silicon
2. Chromium, nickel, and molybdenum
3. Phosphorus, sulfur, and copper
4. Aluminum, titanium, and vanadium

(Explanation: SA516 Gr 60 requires precise control of carbon for strength, manganese for toughness, and silicon for deoxidation in pressure vessel applications. These elements contribute to the material’s mechanical properties and resistance to pressure-related stresses. www.weldingandndt.com)

Q32. In SS304, what role does the chromium content play in enhancing its corrosion resistance properties?

1. Chromium increases hardness and strength
2. Chromium forms a passive oxide layer for corrosion protection
3. Chromium improves ductility and toughness
4. Chromium enhances thermal conductivity

(Explanation: The chromium content in SS304 enables the formation of a passive oxide layer on the surface, providing excellent corrosion resistance by preventing direct contact of the base metal with corrosive environments.)

Q33. How does the carbon content difference between SS304 and SS304L impact their weldability characteristics?

1. Higher carbon content improves weld penetration
2. Lower carbon content reduces the risk of carbide precipitation
3. Carbon content has no effect on weldability
4. Carbon content influences heat-affected zone properties

(Explanation: SS304L’s lower carbon content minimizes carbide precipitation during welding, reducing the susceptibility to intergranular corrosion and enhancing weldability compared to SS304.)

Q34. What mechanical property is crucial for SA516 Gr 60 in pressure vessel applications?

1. Yield strength
2. Hardness
3. Elongation
4. Impact toughness

(Explanation: Impact toughness is vital for SA516 Gr 60 in pressure vessels to withstand sudden loading conditions without fracturing, ensuring structural integrity and safety under varying stress levels.)

Q35. Why is SS304 preferred over SS304L in certain high-temperature applications despite SS304L’s improved corrosion resistance?

1. SS304 offers better thermal conductivity
2. SS304 has higher strength at elevated temperatures
3. SS304L is prone to sensitization at high temperatures
4. SS304 provides superior resistance to thermal expansion

(Explanation: Sensitization in stainless steel like SS304L refers to a process where chromium carbides form along the grain boundaries when exposed to high temperatures, reducing the chromium available to form the protective passive oxide layer. This leads to a depletion of chromium near the grain boundaries, making the material susceptible to intergranular corrosion. In high-temperature environments, this sensitization phenomenon can compromise the corrosion resistance of SS304L, making SS304 a more suitable choice despite its slightly lower resistance to corrosion.)

Q36. What is the Heat-Affected Zone (HAZ)?

1. The area that melts during welding
2. The area of the base metal adjacent to the weld that does not melt but undergoes microstructural changes due to heat
3. The area outside the weld
4. The area where the weld metal is applied

(Explanation: The Heat-Affected Zone (HAZ) is the part of the base metal near the weld that gets heated and change its internal structure but doesn’t melt. During welding, the intense heat from the welding process is concentrated at the joint, causing the base metal in this region to reach high temperatures. Although the HAZ does not melt, the heat is sufficient to alter the microstructure and properties of the metal. This change in the metal’s internal structure can affect its strength, hardness, and other characteristics.)

Q37. What is the minimum specified tensile strength of ASME SA 516 Gr. 70?

1. 70 Mpa
2. 70 Psi
3. 70000 Psi
4. 60 Ksi
5. 700 Mpa

(Explanation: As per ASME Section II Part A, the tensile strength for SA 516 Gr. 70 is between 70 Ksi to 90 Ksi [485 Mpa – 620 Mpa]. Thus, the minimum tensile strength is 70 ksi (which is equivalent to 70,000 psi or 485 MPa)

Q38. What is the minimum required retention period for Procedure Qualification Records (PQRs) and Welder Performance Qualifications (WPQs) according to ASME Section IX?

1. Six months or till the completion of the projects
2. Not specified in ASME Section IX
3. Five years
4. Three months

(Explanation: According to Clause 103.2 of ASME Section IX, it is stated that records must be maintained. However, the code does not specify a minimum or maximum duration for how long these records should be kept.)

Q39. How long is a welder’s qualification valid if they haven’t done any welding with the process they have qualified to, as per ASME Section IX?

1. 3 months
2. 6 months
3. 2 year
4. Not specified in ASME Section IX

(Explanation: As per QW-322.1, According to QW-322.1, a welder’s qualification is valid for 6 months after they last used that welding process. If they don’t use it within that time, the qualification expires.)

Q40. During welder qualification test on a pipe, which area is to be visually inspected as per ASME section IX? 

1. Only root side to check the penetration
2. Entire circumference, inside and outside
3. Only outside if radiography is to be done
4. Only the face and root of the weld
5. Both 1 & 3

(Explanation: As per QW-302.4, during a welder qualification test on a pipe, the entire circumference of the weld, both inside and outside, must be visually inspected.)

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Q41. A radiography test revealed a 10 mm lack of penetration (inadequate penetration without high-low) in a weld. According to API 1104, is this acceptable?

1. Yes, it is acceptable
2. No, it exceeds the limit
3. Only if the aggregate length is within limits
4. It depends on the project specifications

(Explanation: The acceptance criteria for inadequate penetration without high-low are outlined in Clause 9.3.1 of API 1104. The key points are as follows:

• • An individual indication of inadequate penetration must not exceed 1 inch (25 mm).
  • The total length of indications in any continuous 12-inch (300 mm) section of weld should not exceed 1 inch (25 mm).
  • For welds shorter than 12 inches, the aggregate length of indications should not exceed 8% of the total weld length.

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Analysis of the 10 mm Indication:

• A 10 mm lack of penetration is less than the individual limit of 25 mm, making it acceptable based on that criterion.
  • As long as this indication does not contribute to exceeding other limits (like aggregate lengths), it would be considered acceptable under API 1104.)

Q42. What is buttering in welding?

1. The process of applying a protective coating on metal surfaces.
2. The addition of material, by welding, on one or both faces of a joint, prior to the preparation of the joint for final welding.
3. A method for cooling welded joints to prevent cracking.
4. The removal of excess weld material after the welding process is completed.

(Explanation: Buttering is a welding technique where extra material is added to one or both sides of a joint before the final weld is done. This extra layer helps create a smoother connection, making it easier for the final weld to hold together well. By doing this, it reduces the chances of problems like cracking or weak spots in the finished weld.

Q43. What is the main advantage of using Gas Metal Arc Welding (GMAW) over Shielded Metal Arc Welding (SMAW)?

1. GMAW requires no shielding gas.
2. GMAW is generally faster and produces less smoke.
3. GMAW can only be used on thin materials.
4. GMAW is more suitable for outdoor applications.

(Explanation: Gas Metal Arc Welding (GMAW) is often preferred over Shielded Metal Arc Welding (SMAW) because it allows for continuous feeding of wire, resulting in faster welding speeds and reduced smoke production due to absence of flux. In contrast, SMAW uses fixed-length electrodes, which require the welder to replace the electrode once it is consumed. This process can be time-consuming and results in increased fumes due to the flux coating on the electrodes. Consequently, GMAW is often more time efficient and cleaner compared to SMAW.)

Q44. Which of the following is NOT a common non-destructive testing (NDT) method?

1. Ultrasonic Testing (UT)
2. Radiographic Testing (RT)
3. Magnetic Particle Testing (MT)
4. Sandblasting

(Explanation: NDT methods, such as Ultrasonic Testing (UT), Radiographic Testing (RT), and Magnetic Particle Testing (MT), are used to evaluate the integrity of materials without causing damage. Sandblasting, on the other hand, is a surface preparation technique that removes contaminants but does not assess material integrity.)

Q45. In a stress-strain curve, what does the area under the curve represent?

1. Elastic limit
2. Yield strength
3. Toughness
4. Modulus of elasticity

(Explanation: In a stress-strain curve, the area under the curve represents toughness, which is the ability of a material to absorb energy before breaking. Essentially, it shows how much energy a material can handle while being stretched or compressed. The larger the area, the tougher the material is, meaning it can withstand more stress without failing. This is important for materials used in construction and manufacturing, as they need to be strong and flexible enough to endure various forces without breaking.)

Q46. What is the primary purpose of using expansion joints in piping systems?

1. To allow for smooth transitions between different pipe materials
2. To absorb vibrations from nearby machinery
3. To prevent pipes from bursting during extreme temperature changes
4. To provide a flexible connection that accommodates thermal expansion

(Explanation: Expansion joints are specifically designed to handle the expansion and contraction of piping due to temperature fluctuations, preventing stress and potential damage to the system. While options A, B, and C may seem relevant, they do not accurately represent the primary function of expansion joints in maintaining the integrity of piping systems.)

Q47. What is an example of a Quality Control (QC) technique?

1. Developing marketing strategies
2. Conducting non-destructive testing
3. Training employees on new software
4. Scheduling production timelines

(Explanation: Non-destructive testing (NDT) is a quality control technique used to check the material without causing damage. This method helps identify defects or irregularities in products, ensuring they meet quality standards. Unlike the other options listed, which focus more on planning or training, NDT directly assesses the quality of the product itself.)

Q48. What is the main difference between E6010 and E6013 electrodes?

1. E6010 is for smooth bead appearance, E6013 is for deep penetration
2. E6010 is for deep penetration, E6013 is for general-purpose welding
3. Both are the same, just different names
4. E6013 can replace E6010 in all cases

(Explanation: E6010 is a cellulosic electrode used for deep penetration and especially for root passes in pipelines and pressure vessels. E6013 is a rutile-coated electrode, used for general fabrication because it gives a smoother bead but with shallow penetration.)

Q49. Which filler wire is commonly used for MIG welding of mild steel?

1. ER308L
2. ER4043
3. ER70S-6
4. ER309L

(Explanation: ER70S-6 is the standard MIG filler wire for mild steel. It contains deoxidizers like manganese and silicon, which help in welding even on slightly rusty or dirty steel. People often get confused because ER308L (for stainless) and ER4043 (for aluminium) are also popular fillers, but they cannot be used for mild steel.)

Q50. Which filler metal is best for welding 304 stainless steel?

1. ER70S-6
2. ER308L
3. ER4043
4. E6013

(Explanation: ER308L is specifically designed for 304 stainless steel. The “L” means low carbon, which prevents carbide precipitation and keeps the weld resistant to corrosion.)

Q51. Which electrode is best for root pass welding in pipelines?

1. E6013
2. E6010
3. E7018
4. ER70S-6

(Explanation: E6010 has a cellulosic coating, giving deep penetration and a forceful arc that cleans the joint as it welds. This makes it the go-to electrode for root passes in pipelines. E6013 or E7018 cannot achieve the same root penetration.)

Q52. Which filler wire is best for TIG welding aluminium?

1. ER308L
2. ER4043
3. E7018
4. ER70S-6

(Explanation: ER4043 is the most common filler for aluminium alloys because it flows easily and resists cracking. ER5356 is another option, but ER4043 is the first choice for beginners.)

Q53. Which filler metal should be used when welding stainless steel to mild steel?

1. ER308L
2. ER309L
3. ER4043
4. ER70S-6

(Explanation: ER309L is specially designed for dissimilar welding (joining stainless steel to mild steel). Using ER308L (for stainless-to-stainless) will result in cracking and weak joints. This is a very common mistake.).

Q54. Why is E7018 preferred for structural steel welding (bridges, buildings, etc.)?

1. It is the cheapest electrode
2. It has low spatter and easy slag removal
3. It produces welds with high strength and low hydrogen
4. It requires no storage care

(Explanation: E7018 is a low hydrogen, high-strength electrode, making it suitable for critical structures where cracking cannot be tolerated. Beginners often pick E6013 for ease of use, but E7018 gives far better mechanical properties.)

Q55. For MIG welding stainless steel, which shielding gas is normally used?

1. 100% CO₂
2. Argon + 2–5% CO₂
3. 100% Argon
4. Helium only

(Explanation: Stainless steel MIG welding requires an argon-rich gas with a small amount of CO₂ (2–5%). This prevents excessive oxidation while giving arc stability. Using 100% CO₂ will destroy corrosion resistance, and 100% Argon causes poor arc stability.)

Q56. Which test gives yield strength of material?

1. Tensile test
2. Bend test
3. Impact test
4. Hardness test

(Explanation: Tensile test gives yield strength, Ultimate tensile stress – UTS, and % elongation values.)

Q57. Which filler material is most suitable for welding Inconel to carbon steel?

1. E7018
2. ERNiCr-3
3. ER316L
4. E6013
5. Both 2 and 3

(Explanation: Inconel (nickel-based alloy) to carbon steel requires nickel alloy fillers like ERNiCr-3 to prevent cracking and dilution problems. Using stainless steel fillers (like 316L) can cause weld failure.)

Q58. When reviewing a PQR for a new WPS, you note the carbon equivalent (CE) of the base steel is 0.45 %, but the WPS calls for using E7018 only and pre-heat of 50 °C. The thickness is 20 mm. The QA engineer should: 

1. Approve it because E7018 is qualified.
2. Ask for higher pre-heat because CE is high and thickness is 20 mm.
3. Reject the WPS because CE >0.40 % always requires PWHT.
4. Recommend changing to ER70S-2 filler instead of E7018.

(Explanation: The QA engineer should ask for higher preheat because the carbon equivalent (CE) of 0.45% and 20 mm thickness increase risk of weld cracking and HAZ hardening. E7018 is a suitable low-hydrogen electrode, but most of the internationally accepted codes/standards recommend increased preheat above 0.40% CE, and 50 °C may be inadequate for safe welding. Rejecting the WPS or switching to another filler is unnecessary provided WPS parameters are modified accordingly. To learn more about preheat, Please read: https://www.weldingandndt.com/preheating-how-when-and-why/).

Q59. Which of these consumables is least appropriate when welding 304L stainless steel piping in a refinery where chloride contamination is a problem?

1. ER308L filler wire
2. ER309L filler wire
3. E308-16 stick electrode
4. E316L stick electrode

(Explanation: The least appropriate consumable for welding 304L stainless steel piping in a chloride-contaminated refinery environment is ER308L filler wire (option a). Standard 304L (and its matching fillers ER308L/E308-16) are vulnerable to chloride-induced pitting and crevice corrosion, especially above 100 ppm chloride, a scenario often encountered in refinery applications. ER309L adds higher Cr and Ni, while E316L provides Mo for superior chloride resistance, making them better suited for such environments. Therefore, while ER308L is often used for general 304L welding, in high-chloride scenarios it is the least appropriate due to inadequate resistance to chloride attack.)

Q60. During post-weld heat treatment (PWHT) of an alloy steel header in a refinery at 620 °C for 4 hours, the thermocouples are placed but one falls off and isn’t reattached until 2 hours into the hold period. What is the correct QA/QC action?

1. Accept the PWHT because the temperature was maintained for full 4 hours.
2. Reject the part because thermocouple immobilization is mandatory.
3. Continue, but extend the hold period by 2 hours to compensate.
4. Consult the applicable code/specification whether lost thermocouple invalidates the treatment.

(Explanation: The best QA/QC action is option d) Consult the applicable code/specification whether lost thermocouple invalidates the treatment. Most codes require continuous temperature monitoring at critical locations during the entire PWHT hold period, and missing temperature records usually mean the treatment cannot be automatically accepted or extended without review. Depending on the code (such as ASME), the procedure may require repeating or extending the PWHT, but final acceptance or corrective actions should be made in accordance with specific code provisions and project requirements.)

Q61. If a WPS lists an inter-pass temperature not exceeding 200 °C, but actual inter-pass temperature reached 260 °C in a carbon steel weld, what is the likely impact and what should the QA/QC engineer consider?

1. No impact – anything below 300 °C is safe.
2. Possible grain growth in HAZ, toughness loss, so review impact test results and procedures.
3. Must perform full PWHT immediately.
4. It’s only relevant for stainless steels, not carbon steels.

(Explanation: Exceeding the WPS-specified maximum inter-pass temperature can lead to grain growth in the heat-affected zone (HAZ) and decreased toughness, especially for carbon steels. The QA/QC engineer should evaluate the mechanical properties, particularly impact toughness, and review whether the weld still meets code and specification requirements. It is important to follow the WPS strictly, as higher inter-pass temperatures can compromise weld quality and cause non-compliance with procedure qualifications.)

Q62. During welding of a boiler tube joint, the welder reports excessive porosity in the root pass. The base metal is SA-210 Gr A1, and electrode used is E7018. The most likely cause is:

1. Incorrect electrode type
2. Low heat input causing lack of fusion
3. Moisture in electrode or improper baking
4. Excessive interpass temperature

(Explanation: E7018 electrodes are low-hydrogen type and must be baked properly before use. If moisture is absorbed by flux, it releases hydrogen during welding, creating gas porosity. Re-baking and proper storage in a heated oven prevent this issue.)

Q63. During radiographic testing, you observe numerous small, round dark spots clustered together in a localized region of the film. This pattern MOST commonly represents:

1. Slag inclusion
2. Lack of fusion
3. Porosity 
4. Tungsten inclusion

(Explanation: Porosity appears as rounded or nearly spherical dark indications on radiographs, typically gas-shaped, and may be seen scattered randomly or clustered together within the weld zone.)

Q64. A WPS qualified with 100% argon for GTAW root is used on carbon steel with CO₂ mix. QA should:

1. Approve since both are gases
2. Requalify — shielding change is essential variable in GTAW
3. Increase gas flow
4. Reduce interpass temperature

(Explanation: A WPS qualified with 100% argon for GTAW root passes on carbon steel cannot use an argon-CO₂ mix without requalification, as shielding gas composition is an essential variable per ASME Section IX, QW-408.2)

Q65. Which of the following is an essential variable for a visual examination procedure as per ASME Section V?

1. Lighting equipment
2. Sequence of examination
3. Personnel qualifications
4. Remote visual aids

(Explanation: Please refer Table T-921 “Requirements of a Visual Examination Procedure” of ASME section V. As per this table Remote visual aids is an essential variable for visual examination procedure.)

Q66. What should the maximum temperature of the material for measuring the thickness using the manual ultrasonic pulse-echo contact method?

1. 93 °C [200 °F]
2. 100 °C
3. Not specified
4. None of the above

(Explanation: Refer ASME section V, SE-797 clause 1.1, the maximum temperature should be 93 °C [200 °F].)

1. Beam divergence
2. Surface roughness
3. Frequency of the ultrasonic waves
4. All of the above

(Explanation: Ultrasonic flaw detection in UT depends on several factors, with frequency selection being the most prominent. However, other factors also play a crucial role in achieving accurate results. 

• Beam Divergence: As sound waves travel through materials, their beam widens, making it harder to detect small flaws or locate them accurately.
• Surface Roughness: The quality of the material’s surface affects ultrasonic testing’s effectiveness. Rough surfaces scatter ultrasound beams, reducing signal strength and penetration, while smooth surfaces can cause reflections from internal flaws to be missed. 
• Frequency Selection: The frequency of ultrasonic waves used for testing affects the ability to detect specific types of flaws. Higher frequencies offer better detail but less penetration, while lower frequencies penetrate deeper but provide less detail. 

Other factors, such as pulse length, transducer design, and receiver circuitry, can also impact the accuracy of ultrasonic flaw detection. To ensure reliable and effective ultrasonic inspections, it’s essential to understand and optimize these factors based on the specific application.)

Q2. In Ultrasonic Testing (UT), what is the purpose of a reference block, and how does it contribute to the calibration process?

1. To measure the surface roughness of the test material
2. To provide a standard for adjusting the instrument’s sensitivity
3. To act as a reflector for ultrasonic waves
4. To assess the ambient temperature during testing

(Explanation: In Ultrasonic Testing (UT), a reference block is used to provide a standard for adjusting the instrument’s sensitivity during the calibration process. The purpose of the reference block is to ensure that the instrument is accurately detecting flaws in the test material. The block acts as a reflector for ultrasonic waves, allowing the operator to adjust the instrument’s sensitivity until it detects the reflected waves at the same amplitude as the reference block. www.weldingandndt.com

This ensures that the instrument is calibrated to the correct sensitivity level for the specific material being tested. Surface roughness and ambient temperature are not factors that a reference block is used to assess during the calibration process. However, Option 3 i.e. To act as a reflector for ultrasonic waves is partially correct, but the primary purpose of a reference block is calibration rather than acting as a reflector.)

Q3. What is the purpose of the Time-of-Flight Diffraction (TOFD) technique and how does it differ from conventional pulse-echo ultrasonic testing?

1. TOFD is used for measuring material thickness, while conventional pulse-echo is for detecting surface flaws.
2. TOFD provides real-time imaging of internal structures, whereas conventional pulse-echo measures material density. www.weldingandndt.com
3. TOFD is effective for sizing and positioning flaws in welds, while conventional pulse-echo primarily identifies material boundaries.
4. TOFD is suitable for inspecting metallic materials, while conventional pulse-echo is more applicable to non-metallic substances.

(Explanation: The Time-of-Flight Diffraction (TOFD) technique is distinct from conventional pulse-echo ultrasonic testing in that it focuses on detecting and sizing internal flaws rather than identifying material boundaries or surface defects. Unlike pulse-echo, which measures the amplitude of reflected waves, TOFD determines the time of flight of diffracted waves emitted from the edges of flaws, enabling precise measurements of flaw sizes and positions within welds. Additionally, TOFD can be used during production without interrupting operations, providing digital records for future reference, and delivering quick inspection results.)

Q4. In Ultrasonic Testing (UT), what is the purpose of a wedge in the inspection setup, and how does it contribute to the testing process?

1. The wedge is used to measure the velocity of ultrasonic waves in the test material, ensuring accurate calibration.
2. The wedge acts as a reflector, enhancing the detection of surface-breaking flaws.
3. The wedge helps to direct and focus ultrasonic waves into the test material at a desired angle for better penetration and defect detection.
4. The wedge is employed for temperature compensation, ensuring consistent testing results under varying environmental conditions.

(Explanation: In Ultrasonic Testing (UT) Level II, the purpose of a wedge in the inspection setup is to direct and focus ultrasonic waves into the test material at a desired angle for better penetration and defect detection. The wedge is used to position the transducer at an angle to the surface of the specimen so that the shear-wave-refraction angle is optimized. This contributes to the testing process by ensuring that the ultrasonic waves are directed effectively into the material, allowing for improved defect detection and accurate inspection results.)

Q5. In Ultrasonic Testing (UT), describe the purpose of a couplant in the inspection process, and how does it contribute to the effectiveness of ultrasonic wave transmission? 

1. The couplant is used to clean the surface of the test material, ensuring better contact with the ultrasonic probe.
2. The couplant serves as a corrosion inhibitor, preventing degradation of the test material during inspection.
3. The couplant acts as a sound reflector, enhancing the sensitivity of the ultrasonic waves to internal flaws.
4. The couplant facilitates the transmission of ultrasonic waves by eliminating air gaps between the probe and the test material.

(Explanation: The purpose of a couplant in the inspection process is to facilitate the transmission of ultrasonic waves by eliminating air gaps between the probe and the test material. The couplant serves as a medium to ensure efficient transfer of sound energy from the transducer to the test specimen, enhancing the sensitivity of the ultrasonic waves to internal flaws. It does not clean the surface of the test material or act as a corrosion inhibitor, nor does it serve as a sound reflector.)

Q6. Explain the significance of the Near-Field and Far-Field regions during an inspection, and how do these regions impact flaw detection in UT? 

1. The Near-Field region is where surface flaws are primarily detected, while the Far-Field region is critical for assessing internal defects.
2. The Near-Field region is characterized by reduced resolution, making it suitable for shallow flaw detection, whereas the Far-Field region provides better depth penetration.
3. The Near-Field region is where calibration is performed, ensuring accurate instrument settings, while the Far-Field region is where actual flaw detection takes place.
4. The Near-Field and Far-Field regions are interchangeable terms describing the same phase of ultrasonic testing with no distinct impact on flaw detection.

(Explanation: The Near-Field and Far-Field regions are significant during an inspection. Near-Field (also known as the near zone or Fresnel zone) and Far-Field (also known as the far zone or Fraunhofer zone) regions are crucial aspects of ultrasonic testing. The Near-Field region is characterized by extensive fluctuations in sound intensity near the source (reduced resolution and a higher concentration of energy), making it challenging to evaluate flaws accurately . On the other hand, the Far-Field region is where the ultrasonic beam is more uniform, provides better depth penetration and is essential for detecting flaws at greater depths within the material. Hence, optimal detection results are obtained when flaws occur in this area . www.weldingandndt.com

The transition between the Near-Field and Far-Field regions occurs at a distance, which is determined by the transducer diameter, frequency, and sound longitudinal velocity in the medium through which waves are transmitted. The Far-Field region is where most ultrasonic inspection procedures are designed to occur, and the intensity of the sound beam in this region falls off exponentially as the distance from the face of the transducer increases. The Near-Field and Far-Field regions are not interchangeable terms and have a distinct impact on flaw detection.)

Q7. What is the significance of the dead zone, and how does it impact flaw detection in UT?

1. The dead zone is where no ultrasonic waves can penetrate, making it ideal for calibrating instruments.
2. The dead zone is an area near the surface where flaws cannot be detected, affecting the reliability of inspections.
3. The dead zone indicates a region where material thickness is too low for accurate measurements. 
4. The dead zone is a term used to describe the time delay in ultrasonic testing, ensuring precise depth calculations.

(Explanation: Dead zone refers to the region close to the transducer where echoes from the initial pulse are still being received. During this time, the system is unable to detect flaws accurately. The dead zone can impact the reliability of flaw detection, especially for cracks which are on the surface of the material being tested.)

Q8. In Ultrasonic Testing (UT), why is the selection of an appropriate probe or search unit crucial, and how does it impact the inspection process?

1. The probe determines the color contrast in the ultrasonic display, enhancing flaw visibility.
2. The probe influences the calibration process, ensuring accurate measurement of material thickness.
3. The probe or search unit affects the frequency and beam characteristics, influencing flaw detection capabilities. 
4. The probe is responsible for cleaning the test material surface, improving contact for better wave transmission. 

(Explanation: The selection of an appropriate probe or search unit is crucial because it determines the frequency and beam characteristics of the ultrasonic waves. These factors directly impact the system’s ability to detect and characterize flaws within the inspected material. Different probes are chosen based on the specific inspection requirements, material properties, and the depth of flaws that need to be detected.)

Q9. Why angle probes are used, and how do they contribute to the inspection of materials in Ultrasonic Testing (UT)?

1. Angle probes are designed for surface cleaning, improving contact between the ultrasonic waves and the test material.
2. Angle probes facilitate temperature compensation during inspections, ensuring consistent results under varying environmental conditions. www.weldingandndt.com
3. Angle probes are used to adjust the frequency of ultrasonic waves, enhancing the accuracy of calibration.
4. Angle probes enable the inspection of materials at oblique angles, improving the detection of defects beneath the surface. www.weldingandndt.com

(Explanation: Angle probes are designed to allow the inspection of materials at oblique angles, enhancing the detection of defects located beneath the surface. These probes are particularly useful for inspecting welds and other components where the geometry may require testing at angles other than perpendicular to the surface.)

Q10. In Ultrasonic Testing (UT) of welds, what is the primary purpose of employing a phased array probe?

1. To measure the surface roughness of the weld material.
2. To enhance the sensitivity of the ultrasonic waves to internal defects.
3. To facilitate temperature compensation during the inspection.
4. To allow for the inspection of welds at multiple angles without moving the probe.

(Explanation: A phased array probe allows for the inspection of welds at multiple angles without physically moving the probe. This capability improves the flexibility and efficiency of the inspection process, especially in complex weld geometries.)

Q11. What is the name of the curve that shows the relationship between amplitude and distance traveled to reflectors of the same area in ultrasonic testing?

1. BAC curve
2. DAC curve
3. DGS curve
4. TTT curve

(Explanation: The Distance Amplitude Correction (DAC) curve is a graph that shows the relationship between the amplitude of an ultrasonic signal and the distance traveled by the signal to a reflector of a specific size and shape. The DAC curve is used to adjust the instrument’s sensitivity to ensure that signals from reflectors of different sizes and depths are detected and displayed accurately.)

Q12. A weld inspection is conducted using an angle beam probe with a frequency of 5 MHz. If the velocity of the ultrasonic wave in the material is 3000 m/s, What will be the the wavelength of the ultrasonic wave?

1. 0.0006 meters
2. 0.0007 meters
3. 0.0008 meters
4. 0.2 milimters

(Explanation: The wavelength can be calculated using the formula λ = v/f, where λ is the wavelength, v is the velocity of the wave, and f is the frequency of the wave. Substituting the given values, we get λ = 3000/5 x 10^6 = 0.0006 meters or 0.6 millimeters. Therefore, the wavelength of the ultrasonic wave is 0.0006 meters.)

Q13. During ultrasonic weld inspection, a technician uses a straight beam probe with a frequency of 10 MHz. If the ultrasonic waves travel through the weld material at a velocity of 2500 m/s, what will be the wavelength of the ultrasonic wave?

1. 0.21 mm
2. 0.15 mm
3. 0.06 mm
4. 0.00025 m

(Explanation: The wavelength can be calculated using the formula: wavelength (λ) = velocity (v)/ frequency (f). Putting the values, we get: wavelength (λ) = (2500 m/s) / 10 MHz = 0.25 mm = 0.00025 m. Therefore, the wavelength of the ultrasonic wave is 0.00025 meters.)

Q14. In Ultrasonic Testing (UT), what term describes the phenomenon where ultrasonic waves deviate from a straight path when encountering an interface between two different materials?

1. Beam divergence
2. Acoustic impedance
3. Refraction
4. Attenuation

(Explanation: When ultrasonic waves pass through an interface between two different materials, they change direction, and this phenomenon is known as refraction. The angle of refraction depends on the angle of incidence and the difference in acoustic impedance between the two materials. Refraction is an essential concept in ultrasonic testing, as it allows the operator to direct the ultrasonic beam to specific areas of the material being inspected and detect flaws that may be hidden from a straight beam inspection.)

Q15. Why is the concept of “beam divergence” important, and how does it affect the inspection process in UT?

1. Beam divergence ensures proper calibration of the ultrasonic instrument.
2. Beam divergence influences the color contrast of the ultrasonic display.
3. Beam divergence determines the spread of ultrasonic waves, impacting coverage and flaw detection.
4. Beam divergence compensates for temperature variations during inspections.

(Explanation: The concept of “beam divergence” is important because it determines the spread of ultrasonic waves, which can impact coverage and flaw detection. Beam divergence refers to the spreading out of the ultrasonic beam as it travels through a material. This can cause the beam to become wider and less focused, which can reduce the sensitivity of the inspection and make it more difficult to detect flaws. The angle of the beam and the frequency of the ultrasonic waves can also affect beam divergence. Therefore, it is important for technicians to consider beam divergence when selecting the appropriate probe and settings for an ultrasonic weld inspection to ensure accurate and reliable results.)

Q16. Which ultrasonic test frequency would probably provide the best penetration in a 300 mm thick specimen of coarse-grained steel?

1. 2.25 MHz
2. 10 MHz
3. 5 MHz
4. 1 MHz

(Explanation: In ultrasonic testing, higher frequencies generally provide better resolution but less penetration, while lower frequencies offer deeper penetration but lower resolution. Since, we have 300 mm thick specimen of coarse-grained steel, which requires good penetration, a lower frequency would be more suitable. A 1 MHz frequency would have a longer wavelength compared to higher frequencies, allowing it to penetrate deeper into the material.)

Q17. What leads to the attenuation of ultrasonic wave energy as it traverses through a material during testing?

1. Composition and contrast
2. Reflection and refraction
3. Dispersion and diffraction
4. Absorption and scattering

(Explanation: Attenuation in ultrasonic waves refers to the loss of energy as it travels through a material. This loss occurs mainly because of absorption and scattering. Absorption refers to the conversion of sound energy into heat as the wave travels through the material, while scattering involves the redirection of sound waves in different directions due to irregularities or inhomogeneities in the material.)

Q18. Angle beam testing of plate will often miss: 

1. Incomplete penetration at the root.
2. Inclusions that are randomly oriented.
3. Laminations that are parallel to the front surface.
4. A series of small discontinuities.

(Explanation: When laminations run parallel to the front surface of a plate, the sound waves can travel along them smoothly without encountering obstacles that would create reflections. This makes it possible for these defects to go undetected during angle beam testing. The way the defect aligns with the sound beam’s direction is a key factor in determining whether it can be detected effectively using this testing method.)

Q19. What characteristic of particular materials enables them to convert electric energy into mechanical energy and conversely, mechanical energy into electric energy?

1. Piezoelectric effect
2. Gamma-Beta effect
3. Acoustic Impedance
4. Attenuation effect

(Explanation: Certain materials have the unique ability to convert electrical energy into mechanical energy and vice versa, which is referred to as the piezoelectric effect. This phenomenon allows piezoelectric materials to transform mechanical stress into electricity or vice versa. That is why these materials are used in the probes or search units of a Ultrasonic Testing equipment.)

Q20. In ultrasonic testing using an angle probe for weld scanning, if the angle of the probe is 45 degrees and the sound velocity in the material is 3000 m/s, what is the depth of a flaw detected at a time interval of 10 microseconds?

1. 1.5 mm
2. 21.2 mm
3. 4.5 mm
4. 6 mm

(Explanation: The depth (d) of a flaw detected using ultrasonic testing can be calculated using the formula;

d = (V x t)/(2 x cos)

•  Sound velocity in the material
•  Time interval
•  Angle of the probe

Given values are;

• Sound velocity = 3000 m/s
• Time interval =  (which is 10×10^−6 seconds)
• Angle of the probe 

Putting the values d =(3000×10×10^−6)/(2 x cos 

Now, expressing  in millimeters (1 m = 1000 mm)

Q22. Which parameter is calculated by multiplying the density () of a material by its longitudinal wave velocity (V_L) in ultrasonic testing?

1. Ultrasonic Impedance ()
2. Acoustic Conductivity )
3. Acoustic Impedance ()
4. Density Velocity Product ()

(Explanation: In ultrasonic testing, the parameter that is calculated by multiplying the density (ρ) of a material by its longitudinal wave velocity (V_L) is called Acoustic Impedance (AI). Acoustic impedance plays a crucial role by determining how much sound energy bounces back when it encounters different materials. This bouncing back of energy affects how well we can find defects and understand the properties of the material being tested. When there is a big difference in acoustic impedance between materials, more energy reflects back, which can make the testing process less effective in detecting flaws accurately.)

Q23. Consider a steel specimen with a density of 7,850 kg/m³ and a longitudinal wave velocity of 5,900 m/s. Calculate the acoustic impedance of the steel specimen and explain its significance in the context of ultrasonic testing.

1. 46,415,000 kg/(m²s)
2. 35,000,000 kg/(m²s)
3. 52,150,000 kg/(m²s)
4. 40,000,000 kg/(m²s)

(Explanation: Acoustic Impedance (Z) = Density (ρ) X Longitudinal Sound Velocity (V_L)

Given:

• Density of steel specimen (ρ) = 7,850 kg/m³
• Longitudinal wave velocity of steel specimen (V_L) = 5,900 m/s

Substitute the values into the formula:
Z = 7,850 kg/m³ X 5,900 m/s
Z = 46,415,000 kg/(m²s)

Q24. Which type of ultrasonic scan is primarily used to determine the thickness of an object in ultrasonic testing?

1. A-scan
2. B-scan
3. C-scan
4. D-scan

(Explanation: The A-scan is primarily used to measure the thickness of an object in ultrasonic testing by analyzing the time it takes for an ultrasonic wave to travel from the transducer to the object and back.)

Q25. In ultrasonic testing, what is the formula to calculate the wavelength of an ultrasonic wave, and how is it related to the velocity of sound and frequency?

1. Wavelength (λ) = Velocity of wave (v) * Frequency (f)
2. Wavelength (λ) = Velocity of wave (f) / Frequency (f)
3. Wavelength (λ) = Frequency (f) / Velocity of sound (v)
4. Wavelength (λ) = Velocity of sound (v) + Frequency (f)

(Explanation: The wavelength of an ultrasonic wave is calculated by dividing the velocity of sound waves in the material by the frequency of the ultrasonic wave.)

Q26. A plate is 25.4 mm thick. Using the pulse-echo method with a straight beam, the measured elapsed time is 8 microseconds. Which material is it most likely to be?

1. Carbon steel
2. Lead
3. Titanium
4. Aluminum

(Explanation:  To find out the material, we need to calculate the speed of sound in the material using the thickness of the plate and the elapsed time for the pulse-echo method.

1. Given Data:
   • Plate thickness (𝑑) = 25.4 mm = 0.0254 mm
   • Elapsed time (𝑡) = 8 microseconds (µs) = 8×10⁻⁶ s
2. Pulse-Echo Method Explanation:
   • The sound wave travels to the back of the plate and returns, so it covers twice the thickness of the plate.
   • Therefore, the total distance covered by the sound wave is 2𝑑2d.
3. Formula for Speed of Sound: 𝑣=2𝑑/t​
4. Calculate Speed of Sound:

𝑣=(2×0.0254 m)/(8×10⁻⁶ s)

​= 6350 m/s

Now the typical Speeds of Sound in in different materials are:

• Carbon steel: ~ 5900 m/s
• Lead: ~ 2160 m/s
• Titanium: ~ 6100 m/s
• Aluminum: ~ 6320 m/s

Comparing the calculated speed of sound (i.e. 6350 m/s) with the different materials, the calculated value is closest to the speed of sound in aluminum (i,e 6320 m/s).

Conclusion: Hence, the most likely material of the plate is: Aluminum 

Q27. What is the typical frequency range used in commercial ultrasonic testing?

1. 5 MHz and 10 MHz
2. 1 MHz and 10 MHz
3. 10 MHz and 50 MHz
4. 2 MHz and 20 MHz

(Explanation: The choice of frequency in ultrasonic testing is crucial as it affects the penetration depth and resolution of the inspection. Lower frequencies, such as 1 MHz, are capable of penetrating deeper into materials but provide lower resolution images. Higher frequencies, up to 10 MHz, offer higher resolution but have shallower penetration depths. 

Thus, the 1 MHz to 10 MHz range offers a balanced trade-off between penetration and resolution, making it suitable for a wide variety of applications in industrial settings, such as inspecting welds, detecting flaws in metals, and assessing the integrity of structures.)

Q28. Which of the following materials are commonly used in ultrasonic transducers due to their ability to convert electrical energy into mechanical vibrations? 

1. Y cut crystals
2. Piezoelectric elements
3. Magnetostrictive elements
4. All of the above

(Explanation: Certain materials, known as piezoelectric elements, have the special ability to change electrical energy into mechanical vibrations and vice versa. This phenomenon is called the piezoelectric effect. When electricity is applied to these materials, they vibrate and produce sound waves. Similarly, when these materials are exposed to sound waves, they generate an electrical signal. 

Hence, piezoelectric materials are ideal for ultrasonic transducers because they can both create and detect sound waves. When an electric field is applied to piezoelectric materials, they change shape slightly, producing mechanical vibrations (sound waves). When they experience mechanical stress (like sound waves hitting them), they generate an electrical signal. This dual capability is essential for the effective operation of ultrasonic testing, allowing us to inspect materials like metals and ceramics for cracks or defects to ensure they are safe and reliable.

Examples of piezoelectric materials are Lithium sulfate, barium titanate, and lead metaniobate. 

A brief explanation of the other options given in this question and how they differ from piezoelectric elements is provided below:

Y-cut crystals: These refer to a specific orientation of a quartz crystal used in electronic devices. They are not the same as the piezoelectric materials mentioned in the question, as Y-cut crystals are primarily used for their frequency stability in oscillators and filters, rather than for generating mechanical vibrations. 

Magnetostrictive elements: These materials change their shape or size when exposed to a magnetic field. Unlike piezoelectric elements, which respond to mechanical stress or pressure, magnetostrictive elements rely on magnetic fields to induce vibrations.)

Q29. In which of the following forms can sound propagate through various materials?

1. Longitudinal Waves
2. Shear Waves
3. Surface Waves
4. All of the Above

(Explanation: Sound can propagate as all of the above: longitudinal waves, shear waves, and surface waves. Let’s understand more about these waves;

• Longitudinal Waves: These waves occur when particles in the medium move in the same direction as the wave itself. This is the primary way sound travels through gases and liquids, creating areas of compression and rarefaction. 
• Shear Waves: Also known as transverse waves, these involve particle movement that is perpendicular to the direction of wave travel. Shear waves can only propagate through solids due to their structural rigidity.
• Surface Waves: These are waves that travel along the surface of a medium. They are a combination of longitudinal and shear waves. Imagine ripples on a pond. 

So, depending on the medium through which sound is traveling (solid, liquid, or gas), it can propagate through all of these wave types.)

Q30. During ultrasonic inspection (UT) on a 20 mm thick weld, an indication having length 2 mm observed, which is characterised as lack of fusion between the base metal and weld metal. As per the acceptance criteria in ASME Section VIII Division 1, this defect is:

1. Not Acceptable
2. Acceptable
3. Acceptance depends upon the depth of flaw
4. None of above

(Explanation: According to ASME Section VIII Division 1, any indication characterized as a lack of fusion is unacceptable regardless of its size. Since the 2 mm long indication in the 20 mm thick weld has been characterized as lack of fusion, it would be unacceptable per ASME Section VIII Division 1 criteria, regardless of its size or depth.

To learn more about the acceptance criteria, Please read: https://www.weldingandndt.com/acceptance-criteria-for-weld-defects/)

Figure 1

Q31. Figure 1 (shown above) illustrates an ultrasonic test on a job. What does indication ‘A’ represent?

1. The initial pulse or front-surface indication
2. The discontinuity indication
3. The back-surface reflection
4. Baseline

(Explanation: Point ‘A’ represents the initial pulse, the emitted ultrasonic wave from the transducer, marking the sound wave’s entry into the material and appearing near time zero on the A-scan. This initial pulse creates a near-surface “dead zone” because the transducer’s subsequent “ring down” prevents the clear reception of early echoes from shallow depths, which are masked by the pulse’s tail. Consequently, the area directly beneath the transducer cannot be reliably scanned for defects during and immediately after the initial pulse, a limitation of single-element pulse-echo UT.)

Q32. In Figure 1, indication B represents:

1. The initial pulse or front-surface indication
2. The discontinuity indication
3. The back-surface reflection
4. Baseline

(Explanation: Point ‘B’ represents a defect echo, a signal that arises when the emitted ultrasonic wave encounters a discontinuity (the defect) within the test material and reflects back towards the transducer.)

Q33. In Figure 1, indication C represents:

1. The initial pulse or front-surface indication
2. The discontinuity indication
3. The back-surface reflection
4. Baseline

(Explanation: Point ‘C’ represents the back surface reflection, also known as the back wall echo, a signal generated when the ultrasonic wave travels through the entire material thickness, reflects off the back surface, and returns to the transducer. Appearing latest on the A-scan, its position indicates the material’s total thickness based on the sound’s round-trip travel time.)

Q34. What is the skip distance on a 10 mm plate with a 70 degree angle probe?

1. 20 mm
2. 100 mm
3. 10 mm
4. 55 mm

(Explanation: To calculate the skip distance (S) for a 10 mm plate with a 70-degree angle probe, we use the formula: Skip Distance (S) 

Where:

•  is the thickness of the plate (10 mm)
•  is the refracted angle of the probe (70 degrees)

Substituting the values: 

Skip distance represents the surface distance from the probe’s index point to where the sound beam reflects off the back wall and returns to the surface. To learn more about skip distance and beam path, please read: https://www.weldingandndt.com/angle-probe-calculation-for-ut/).

For question answer video lectures on UT, please watch:

• Hindi: https://youtu.be/Mb0ekRAkS_g
• English: https://youtu.be/GcVqVlHXqZI

1. Submerged Arc Welding (SAW)
2. Gas Tungsten Arc Welding (GTAW/TIG)
3. Shielded Metal Arc Welding (SMAW/Stick)
4. Flux-Cored Arc Welding (FCAW)

(Explanation: Submerged Arc Welding (SAW) is the most suitable choice for large-scale, high-production applications. SAW offers high deposition rates, deep penetration, and minimal spatter, making it highly efficient for welding thick sections. It’s widely used in industries like shipbuilding, construction, and manufacturing.)

Q2) Which welding process is best suited for precise control, clean welds, and applications requiring thin sections or intricate details?

1. Submerged Arc Welding (SAW)
2. Gas Tungsten Arc Welding (GTAW/TIG)
3. Shielded Metal Arc Welding (SMAW/Stick)
4. Flux-Cored Arc Welding (FCAW)

(Explanation: Gas Tungsten Arc Welding (GTAW/TIG) is the preferred choice for applications requiring precise control, clean welds, and the ability to weld thin sections. TIG welding uses a non-consumable tungsten electrode and a shielding gas, allowing for precise control of the arc and a clean weld bead. It’s commonly used in industries like aerospace, automotive, power plants, refineries and electronics.)

Q3) Which welding process is best suited for outdoor applications where portability and ease of use are essential?

1. Submerged Arc Welding (SAW)
2. Gas Tungsten Arc Welding (GTAW/TIG)
3. Shielded Metal Arc Welding (SMAW/Stick)
4. Flux-Cored Arc Welding (FCAW)

(Explanation: Shielded Metal Arc Welding (SMAW/Stick) is the most suitable choice for outdoor applications where portability and ease of use are essential. SMAW uses a coated electrode that provides both filler metal and shielding gas, making it a convenient and portable option. It’s widely used in construction, maintenance, and repair applications.)

Q4) What is the slag length acceptable for a 75 mm thick weld, as per ASME Sec VIII Div. 1?

1. 4 mm
2. 6 mm
3. 19 mm
4. None of above

(Explanation: According to ASME Section VIII Division 1, for welds over 57 mm (2¼ inches) thick, the maximum acceptable length of slag or any defects other than the crack, lack of penetration, and lack of fusion 19 mm (¾ inch). Please note that the indications characterized as cracks, lack of fusion, or incomplete penetration are unacceptable regardless of length. To learn more about the acceptance criteria, Please read: https://www.weldingandndt.com/acceptance-criteria-for-weld-defects/)

Q5) When considering the MIG/MAG welding process which of the following metal transfer modes would be the most suited to the welding of thick plates over 25mm, flat welding position?

1. Dip transfer
2. Pulse transfer
3. Spray transfer
4. Globular transfer

(Explanation: Spray transfer is often preferred for welding thick plates in the flat position due to its high deposition rates, good penetration, and overall efficiency. While pulsed transfer can also be effective, spray transfer is a common choice for thicker materials in flat welding positions.)

Q6) Poor penetration would be found in MIG/MAG welded steels when using:

1. Argon + 20 % CO2
2. CO2
3. Pure Argon
4. Argon + 5 % CO2

(Explanation: Pure Argon tends to produce a wider, shallower penetration profile, and in certain applications, it may result in poor penetration. The addition of CO2 helps improve the welding process by providing better arc stability and deeper penetration.)

Q7) In the TIG welding process, slope-in/slope-out capability is useful in order to:

1. Avoid start porosity and crater pipes
2. Reduce the risk of tungsten inclusions
3. Stabilise the arc
4. Allow more time for the filler metal to melt

(Explanation: In TIG welding, slope-in and slope-out capability, also known as “amperage ramping” or “current up/down slope,” is useful to avoid start porosity and crater pipes. Slope-in helps gradually increase the welding current at the start of the weld to avoid porosity, and slope-out gradually decreases the current at the end to prevent the formation of crater pipes. This feature helps in achieving smoother and more controlled starts and stops in the welding process.)

Q8) Which defect is NOT normally associated with TIG?

1. Tungsten inclusion
2. Crater pipe
3. Spatters
4. Lack of fusion

(Explanation: Spatters are normally not associated with TIG (Tungsten Inert Gas) welding. TIG welding typically produces a clean and precise weld with minimal spatters compared to processes like MIG (Metal Inert Gas) welding, which is more prone to spatter.)

Q9) Argon purging on the root side is necessary in the TIG welding of stainless steel to:

1. Obtain full penetration
2. Obtain full fusion
3. Avoid porosity in the root
4. Obtain a satisfactory weld surface finish

(Explanation: Argon purging on the root side in TIG welding of stainless steel is necessary to avoid porosity in the root. Purging with argon creates an inert atmosphere on the backside of the weld, preventing the formation of porosity caused by exposure to oxygen.)

Q10) Tungsten inclusion occur due to:

1. High current
2. Incorrect vertex angle
3. Lack of welder skill
4. All of the above

(Explanation: Tungsten electrodes are not consumed during welding. However, sometimes the tungsten melts and go inside the molten weld pool, which results in tungsten inclusion. Tungsten inclusion can occur due to various factors, including an incorrect vertex angle, high current, and a lack of welder skill. Each of these factors can contribute to the presence of tungsten particles in the weld, leading to tungsten inclusion.)

Q11) In MAG/CO2 welding which parameter gives the greatest control of weld appearance during dip transfer or short-circuiting welding?

1. Wire stick-out length
2. Amperage
3. Wire feed speed
4. Inductance

(Explanation: Inductance control, if available on the welding equipment, can influence the characteristics of the welding arc, affecting things like arc stability and control of the molten metal transfer. Adjusting the inductance can have an impact on the appearance of the weld.)

Q12) What type of current is used for TIG welding of carbon steels:

1. DCEN
2. AC
3. DCEP
4. None of the above

(Explanation: DCEN, or straight polarity, is commonly used for TIG (Tungsten Inert Gas) welding of carbon steels. In this configuration, the electrode (tungsten) is connected to the negative terminal, and the workpiece is connected to the positive terminal.)

Q13) Spatter may be finely controlled during MIG/MAG (GMAW) welding by:

1. Adjusting the inductance control
2. Using CO2 gas
3. Increasing the arc voltage
4. Welding with no gas

(Explanation: The inductance control is a parameter that can be adjusted on some welding machines to influence the welding process, and it plays an important role in controlling spatter. Inductance control on a welding machine regulates the rate of current rise and fall during the welding process. By adjusting the inductance control, one can influence the characteristics of the welding arc.)

Q14) Which of the following electrodes and current types may be used for the TIG welding of nickel and its alloys?

1. Cerium electrode, DC –ve
2. Zirconium electrode, AC
3. Thorium electrode, DC +ve
4. All of the above may be used

(Explanation: When TIG welding, nickel and its alloys, a zirconium electrode with AC (alternating current) is commonly used. The use of AC helps to maintain a stable arc and provides good penetration and cleaning action on the base metal, which is beneficial for welding nickel alloys.)

Q15) The main reason why the use of semi-automatic dip transfer MIG/MAG welding is prohibited for some high-integrity applications is because?

1. It may produce a lot of spatter
2. The weld metal toughness is always poor
3. It very often gives lack of sidewall fusion defects
4. Wire feeding problems mean there are usually far too many stop-start regions

(Explanation: The semi-automatic dip transfer mode in MIG/MAG welding is characterized by the intermittent transfer of molten metal in the form of droplets from the welding wire to the weld pool. The reason why it is often prohibited for high-integrity applications is that it can very often result in a lack of sidewall fusion defects.)

Q16) Which of the following current types would be used for welding aluminum with the TIG welding process?

1. AC
2. DC +ve electrode
3. DC –ve electrode
4. All of the above could be used successfully

(Explanation: AC is effective for welding aluminum because it helps in cleaning the aluminum oxide layer from the surface during the welding process. This prevents oxide buildup on the tungsten electrode and contributes to better overall weld quality when working with aluminum.)

Q17) Which of the following welding processes would you expect to use a collet:

1. TIG
2. MIG / MAG
3. MMA
4. All of the above

(Explanation: A collet is commonly used in TIG (Tungsten Inert Gas) welding. Collet is the part of the torch assembly and is responsible for holding and securing the tungsten electrode. The collet exerts pressure on the electrode, keeping it in place while allowing for adjustments and replacements as needed.)

Q18) The spray transfer mode of GMAW is characterized by……..

1. Giving deep penetration
2. Being suitable for positional welding
3. Giving excessive spatter
4. All of the above

(Explanation: In the spray transfer mode, the welding wire is typically charged with high current, and the metal transfer occurs in a spray-like fashion. This mode is often used in applications where deep penetration into the base metal is required.)

Q19) In positional MMA welding (SMAW) on pipework, welders are having difficulty in obtaining good capping profiles when welding in the overhead position. You would..

1. Advise them to increase the current
2. Advise them to increase the voltage
3. Ask for a new welding team
4. Suggest the use of a smaller diameter electrode

(Correct Answer: d. Suggest the use of a smaller diameter electrode.

A smaller diameter electrode can offer better control and deposition of weld metal in positional welding. It allows for more precise placement of the filler metal, making it easier to achieve a desirable capping profile, especially in challenging positions like overhead welding.

Conflict: b. Advise them to increase the voltage.

Increasing the voltage is often a more common and straightforward adjustment to improve wetting and fusion of the weld metal, especially in overhead welding positions. It can help achieve better capping profiles by promoting smoother and more consistent deposition.

So, both Option b and Option d can be relevant suggestions to address the issue. The choice between the two may depend on the specific welding conditions and the welder’s preference or experience.)

Q20) MMA electrode can be grouped into three main types. These are:

1. Basic, Cellulosic and Rutile
2. Neutral, Cellulosic and Rutile
3. Basic, Cellulosic and neutral
4. None of the above

(Explanation: Basic, Cellulosic & Rutile is a grouping of MMA Welding (SMAW) based on their flux coverings. Examples are;

• Basic Electrode Example: E7018
• Cellulosic Electrode Example: E6010
• Rutile Electrode Example: E6013)

Q21) Which of the following welding processes would give the highest heat input when using typical parameters?

1. Tungsten Inert Gas welding
2. Manual Metal Arc welding
3. Submerged Arc welding
4. Metal Active Gas welding

(Explanation: The continuous feeding of the electrode and the use of granular flux contribute to sustained and intense heat, making SAW effective for welding thick materials and achieving deep penetration. www.weldingandndt.com)

Q22) The term “low hydrogen electrode” is often used for certain electrodes. What type of covering will they have?

1. Cellulosic
2. Rutile
3. Basic
4. Acid

(Explanation: The term “low hydrogen electrode” is often associated with electrodes that have a basic covering. These electrodes are designed to deposit weld metal with low levels of hydrogen, which is crucial for preventing hydrogen-induced cracking in the weld metal. Basic-coated electrodes are often used in applications where hydrogen-induced cracking is a concern, such as welding high-strength steels and critical applications.)

Q23) MMA welds made with damaged electrode coatings are subject to:

1. Porosity
2. Undercut
3. Excessive penetration
4. Excessive bead height

(Explanation: Damage electrode coating can lead to contamination and the release of gases during welding, resulting in porosity in the weld. Porosity is the formation of small cavities or voids within the weld metal, and it can weaken the weld and adversely affect its mechanical properties.)

Q24) What are the most common welding hazards?

1. Fumes, burns, electric shock
2. Only fumes
3. Only burns
4. Only electric shock

(Explanation: Welding comes with several hazards, and the most common ones include fumes, burns, and electric shock! When welding, harmful fumes are released from the materials being welded and the filler metals, which can pose serious health risks if inhaled. Burns are another major concern, as the intense heat and sparks produced during welding can easily cause skin injuries. Additionally, electric shock is a significant risk when working with welding equipment, especially if proper safety precautions aren’t followed. While each of these hazards is serious on its own, they often occur together in a welding environment, making it crucial for welders to be aware of all three and take appropriate safety measures to protect themselves.)

Q25) What is the difference between MIG, TIG, and stick welding?

1. Power source, filler metal, shielding gas
2. Only filler metal
3. Only shielding gas
4. Only power source

(Explanation: The key differences between MIG, TIG, and stick welding lie in their power source, filler metal, and shielding gas! MIG (Metal Inert Gas) welding uses a continuous wire feed as filler metal and requires an inert gas, typically argon or a mix of gases, to shield the weld pool. TIG (Tungsten Inert Gas) welding employs a non-consumable tungsten electrode and can use a separate filler metal, also shielded by an inert gas like argon. In contrast, stick welding (Shielded Metal Arc Welding) uses a consumable electrode that serves as both the filler metal and the shielding mechanism through its flux coating, without needing an external gas supply. Understanding these differences helps welders choose the right process for their specific applications and materials!)

Q26. When a dissimilar weld between carbon steel and stainless steel shows brownish or blue tint on the stainless side after welding, it most likely indicates:

1. Excellent fusion and clean weld surface
2. Chromium oxide (heat tint) formation due to overheating
3. Moisture entrapment during welding
4. Proper shielding gas coverage

(Explanation: That brown or rainbow shade isn’t a sign of “perfect fusion” — it’s heat tint. During welding, chromium at the surface reacts with oxygen to form chromium oxide, depleting the protective Cr layer. This weakens corrosion resistance. The remedy? Pickling and passivation to restore the passive film.)

1. Tungsten Inert Gas welding
2. Manual Metal Arc welding
3. Submerged Arc welding
4. Metal Active Gas welding

(Explanation: The continuous feeding of the electrode and the use of granular flux contribute to sustained and intense heat, making SAW effective for welding thick materials and achieving deep penetration.)

Q2. Autogenous welding refers to what?

1. Welding with filler wire
2. Mechanised welding
3. Welding without filler wire
4. Manual welding

(Explanation: Autogenous welding refers to welding without filler wire. In autogenous welding, the fusion of base metals is achieved without use of additional filler material. The weld joint is formed solely by melting and solidifying the edges of the workpieces. This process is commonly used when the base metal itself is sufficient to provide the necessary material for creating a sound weld joint.)

Q3. Synergic welding is associated with which welding process?

1. GMAW
2. MMAW/SMAW
3. GTAW
4. SAW

(Explanation: In a synergic welding system, changes to one parameter lead to automatic adjustments in others to maintain an optimal welding condition. It involves a welding power source that automatically adjusts both voltage and wire feed speed in a coordinated or “synergic” manner. Synergic GMAW systems are designed to enhance efficiency and control in the welding operation.)

Q4. In which of the following welding process, Carbon Dioxide gas is used?

1. GMAW
2. MMAW/SMAW
3. GTAW
4. SAW

(Explanation: In GMAW, CO2 can be used as the shielding gas, the process is sometimes referred to as MAG (Metal Active Gas) welding because CO2 is not an inert gas. The use of CO2 in GMAW/MAG welding helps protect the weld pool from atmospheric contamination and provides a stable arc for the fusion of metals.

Q5. The term “low hydrogen electrode” is often used for certain electrodes. What type of covering will they have?

1. Cellulosic
2. Rutile
3. Basic
4. Acid

(Explanation: The term “low hydrogen electrode” is often associated with electrodes that have a basic covering. These electrodes are designed to deposit weld metal with low levels of hydrogen, which is crucial for preventing hydrogen-induced cracking in the weld metal. Basic-coated electrodes are often used in applications where hydrogen-induced cracking is a concern, such as welding high-strength steels and critical applications.)

Q6. The composition of steel is changed from 0.15% carbon & 0.6% manganese to 0.2% carbon & 1.2% manganese. Might this influence the incidence of:

1. Porosity
2. Cracking in the weld area
3. Undercut for fillet welds
4. Lack of root fusion defects

(Explanation: Let’s analyse each potential effect:

• Porosity: Increasing manganese from 0.6% to 1.2% is likely to reduce porosity in the weld because manganese acts as a deoxidizer, lowering oxygen content.
• Cracking in the weld area: Increasing carbon and manganese can influence the hardenability of the steel, potentially making it more susceptible to cracking. Hence, it could increase the risk of cracking, particularly if not properly controlled during welding.
• Undercut for fillet welds: Undercutting is often influenced by welding parameters and the base metal composition. More carbon might slightly increase undercut, but welding parameters and technique also play a significant role in undercutting for fillet welds.
• Lack of root fusion defects: The rise in manganese content is likely to improve root fusion, contributing to better penetration and fusion in the weld.)

Q7. Which of the following alloys is nonmagnetic?

1. 4% Chromium Molybdenum
2. 12% Chromium
3. Austenitic Stainless Steel
4. 9% Nickle Steel

(Explanation: Let’s analyse each option:

• 4% Chromium Molybdenum: Alloys with chromium and molybdenum are typically magnetic, and this alloy is no exception.
• 12% Chromium: Chromium alloys are usually magnetic, and the high chromium content in this alloy contributes to its magnetic properties.
• Austenitic Stainless Steel: Austenitic stainless steels, with high nickel content and a face-centered cubic crystal structure, are generally nonmagnetic.
• 9% Nickel Steel: Nickel alloys, like this one with a significant nickel content, are typically nonmagnetic due to the austenitic structure imparted by nickel.

So, while both c & d are considered nonmagnetic, austenitic stainless steel is usually consistently nonmagnetic, and 9% Nickel Steel may show minimal magnetic effects under certain conditions. Hence most appropriate answer will be “Austenitic stainless steel”.)

Q8. Addition of which element in steel increase its toughness at sub-zero temperature?

1. Carbon
2. Chromium
3. Nickel
4. Molybdenum

(Explanation: When it comes to toughness at sub-zero temperatures, Nickel is often more prominently associated with this property. Nickel helps maintain ductility and impact resistance even in cold conditions. Molybdenum, indeed, plays a crucial role in improving the toughness of steel, especially at elevated temperatures. It enhances hardenability and strength.)

Q9. Which of the following elements help in improved creep properties at elevated temperature in steel?

1. Tungsten
2. Manganese
3. Molybdenum
4. Carbon

(Explanation: Molybdenum improves the creep properties of steel at elevated temperatures by forming stable carbides, inhibiting grain coarsening, and enhancing resistance to deformation through solid solution strengthening.

Molybdenum is like a superhero for steel at high temperatures. It forms special structures that prevent the steel from getting weaker and deforming when it’s really hot. It’s like adding reinforcements to a building, making the steel stronger and more resistant to damage, especially over time at high temperatures.)

Q10. Tensile strength can be increased in steel by:

1. Annealing
2. Galvanising
3. Addition of carbon
4. Casting

(Explanation: Carbon is a common alloying element in steel and contributes significantly to its strength. The relationship between carbon content, hardness, and tensile strength in steel is indeed nuanced. Up to a certain point, increasing carbon content in steel tends to increase its tensile strength but excessive carbon can lead to increased hardness and brittleness.

Annealing is a heat treatment process that is often used to improve the ductility and reduce hardness in steel, but it doesn’t directly increase tensile strength).

Q11. Which of the following chemical elements has the greater effect on the hardenability of a steel plate?

1. Molybdenum
2. Chromium
3. Titanium
4. Carbon

(Explanation: The hardenability of steel refers to its ability to be hardened through heat treatment, typically by quenching. Among the options provided:

Carbon: Carbon has a significant impact on hardenability. It is a key element in the formation of various hardening phases, such as martensite, during the quenching process. Increasing carbon content generally improves hardenability, but it needs to be within a certain range to avoid excessive brittleness.

Molybdenum, Chromium, Titanium: While these elements can influence the overall properties of steel, their direct effect on hardenability is generally not as pronounced as that of carbon.

In summary, while all the elements listed can contribute to the overall properties of steel, the one with the greater effect on hardenability among the options provided is Carbon.)

Q12. To prevent the hardening and cracking of High Carbon Steel plate during flame cutting, it is advisable to:

1. Pre-heat the plate
2. Soak the plate in oil
3. Cool the plate quickly after cutting
4. Increase the cutting Oxygen pressure

(Explanation: Pre-heating the high carbon steel plate before flame cutting helps reduce the temperature gradient between the heated and unheated regions, minimizing the risk of hardening and cracking during the cutting process.)

Q13. Re-crystallization during annealing is used to make steel:

1. Softer
2. Harder
3. Tougher
4. Stronger

(Explanation: Annealing, including re-crystallization annealing, is a heat treatment process that promotes the formation of new, strain-free grains in the steel. This results in a softer and more ductile material.)

Q14. On which of the following, you will not be able to perform MPI?

1. A low carbon steel butt welded joint
2. An Austenitic Stainless steel fillet welded T joint
3. A medium carbon steel fillet welded lap joint
4. All of the above

(Explanation: Austenitic stainless steel is generally nonmagnetic and may not be well-suited for traditional MPI. Other inspection methods like dye penetrant or ultrasonic testing might be more appropriate.

Q15. SMAW (MMA) welding of low alloy steels is more likely to be performed with?

1. Rutile electrodes
2. Cellulosic electrodes
3. Neutral electrodes
4. Basic hydrogen controlled electrodes

(Explanation: Low alloy steels are a category of steels that contain a relatively low percentage of alloying elements compared to high alloy steels. The term “low alloy” is relative and typically refers to steels where the total alloying elements constitute less than 5% of the steel’s composition.

For low alloy steels, The basic hydrogen controlled electrodes are often preferred because they provide good mechanical properties and are effective in preventing the formation of hydrogen-induced cracking, which is a common concern when welding low alloy steels. Example of basic hydrogen controlled electrodes are;

• E7018: This is a commonly used basic hydrogen-controlled electrode for welding carbon and low alloy steels. It provides good mechanical properties and is known for its versatility.
• E7016: Another basic hydrogen-controlled electrode suitable for welding carbon and low alloy steels. It is often used in applications where higher penetration is required.
• E7015: This electrode is also basic-coated and low hydrogen. It is used for welding carbon and low alloy steels in various applications.

Q16. In MMA welding (SMAW) what parameter is used to control the penetration into the base material?

1. Voltage
2. Welding speed
3. Iron powders in the coating
4. Current

(Explanation: Current plays a significant role in controlling the depth of penetration during welding. Increasing the current generally leads to greater heat input and deeper penetration, while decreasing the current can result in shallower penetration.)

Q17. Consumable electrode, flux shielded, manual process is a description of which welding process?:

1. FCAW
2. SAW
3. GTAW/TIG
4. SMAW/MMAW

(Explanation: The SMAW (MMAW) electrodes are flux shielded and gets consumed during the welding and it is a manual process.)

Q18. Why high O.C.V. is required for MMA welding?

1. To initiate the arc
2. To obtain penetration
3. To avoid lack of fusion
4. MMA welding does not have a high O.C.V.

(To strike an arc, a relatively high voltage is required to generate a spark between the electrode and base metal. This is known as the open circuit voltage (OCV) and is typically ~50-~90V.

The arc is initiated when the electrode is brought close to the workpiece, and the high O.C.V. helps to establish a stable arc by overcoming the resistance between the electrode and the workpiece.)

Q19. Which of the following butt-weld preparations is generally most susceptible to ‘lack of side wall fusion’ during MMA welding?

1. A ‘U’ preparation
2. A ‘V’ preparation
3. A ‘double V’ preparation
4. Lack of side wall fusion does not exist with MMA

(Explanation: A groove with a U-shaped profile is more susceptible to ‘lack of side wall fusion’ during MMA welding. The U-shaped groove makes it challenging to achieve proper fusion along the sidewalls of the joint.)

Q20. Which arc welding process utilizes a non-consumable electrode? 

1. MIG
2. TIG
3. MMA
4. All of the above

(Explanation: In TIG welding, a tungsten electrode is used to generate the arc which produces the necessary heat for welding. However, the electrode is not consumed during welding. If required, additional filler metal is used.)

Q21. Which welding process is best for welding thick sections of metal?

1. Gas Tungsten Arc Welding (GTAW/TIG)
2. Shielded Metal Arc Welding (SMAW/Stick)
3. Flux-Cored Arc Welding (FCAW)
4. Submerged Arc Welding (SAW)

(Explanation: When it comes to welding thick sections of metal, Submerged Arc Welding (SAW) is the top choice! This process is specifically designed for high deposition rates and deep penetration, making it ideal for thicker materials. The arc is shielded by a blanket of granular flux, which protects the weld from contamination and helps to produce clean, strong welds with minimal spatter. While other methods like Shielded Metal Arc Welding (SMAW/Stick) and Flux-Cored Arc Welding (FCAW) can also handle thicker materials, they typically don’t match the efficiency and quality of SAW for heavy-duty applications. So, if you’re tackling thick metal sections, go with SAW for the best results!)

Q22. Which welding process is commonly used for welding aluminum and magnesium?

1. Submerged Arc Welding (SAW)
2. Gas Tungsten Arc Welding (GTAW/TIG)
3. Shielded Metal Arc Welding (SMAW/Stick)
4. Flux-Cored Arc Welding (FCAW)

(Explanation: When it comes to welding aluminum and magnesium, Gas Tungsten Arc Welding (GTAW or TIG) is the go-to process! TIG welding offers excellent control over heat input, which is crucial for these lightweight metals that can easily warp or burn through. The process uses a non-consumable tungsten electrode and an inert gas, typically argon, to shield the weld area from contamination, ensuring clean and strong welds. While other methods like Submerged Arc Welding (SAW) and Shielded Metal Arc Welding (SMAW) have their applications, they are generally less effective for aluminum and magnesium due to their unique properties. So, for high-quality welds on these metals, stick with TIG welding! (www.weldingandndt.com)

Q23. In welding, what does “spatter” refer to?

1. Small droplets of molten metal expelled during welding
2. A type of welding defect
3. The process of cleaning the weld
4. A welding technique

(Explanation: Spatter in welding refers to small droplets of molten metal that are expelled from the weld pool during the welding process. These droplets can adhere to the surrounding surfaces, creating a rough and uneven appearance, which is generally undesirable as it can affect the quality and aesthetics of the weld. Common causes of spatter include high welding current, incorrect polarity, poor shielding gas coverage, and improper welding techniques. To minimize spatter, welders should reduce the welding current, ensure correct polarity settings, improve shielding gas coverage, and use proper welding techniques while maintaining a steady hand. To learn more about welding defects, please click here.)

1. SAW
2. MMA
3. TIG
4. MIG

(Explanation: In TIG welding, a tungsten electrode is used to create an arc, and a separate filler material may be added to the weld pool as needed. The electrode itself is not consumed during the welding process.)

Q2. MMA welding (SMAW) of low alloy steels is more likely to be performed with?

1. Rutile electrodes
2. Cellulosic electrodes
3. Neutral electrodes
4. Basic hydrogen controlled electrodes

(Explanation: Basic hydrogen controlled electrodes electrodes are often preferred because they provide good mechanical properties and are effective in preventing the formation of hydrogen-induced cracking, which is a common concern when welding low alloy steels. Examples are;

• E7018: This is a commonly used basic hydrogen-controlled electrode for welding carbon and low alloy steels. It provides good mechanical properties and is known for its versatility.
• E7016: Another basic hydrogen-controlled electrode suitable for welding carbon and low alloy steels. It is often used in applications where higher penetration is required.
• E7015: This electrode is also basic-coated and low hydrogen. It is used for welding carbon and low alloy steels in various applications.)

Q3. Which of the following can be used as a shielding gas in TIG Welding?

1. Argon
2. Helium
3. Nitrogen
4. All the above

(Explanation: For TIG welding, the primary gases which are used are; Argon, Helium and Hydrogen. However, Sometimes a mixture of Argon and Nitrogen (up to 5%) is also used for back purging of duplex stainless, austenitic stainless steels and copper alloys. Nitrogen gas is not used for mild steels because it can cause age embrittlement).

Q4. MIG welding tends to be susceptible to lack of fusion problems. This is because of:

1. Poor maintenance of equipment
2. Incorrect settings
3. Poor inter run cleaning
4. All of the above

(Explanation: Lack of fusion in welding can be caused by poor equipment maintenance, like faulty wire feeders or worn contact tips. Incorrect settings, such as voltage or wire speed, can also lead to insufficient heat. Additionally, not cleaning between welding passes can result in issues due to spatters, or contaminants.)

Q5. What is the correct procedure for handling electrode E6010 (AWS A5.1)?

1. Bake for 1 hour
2. Baking not required
3. Baking for 1 hour at 100ºC and stored at 70ºC
4. Baking for 1 hour at 180ºC

(Explanation: Usually Low-hydrogen electrodes like E7018 require baking. E 6010 (AWS A5.1) fall outside the low-hydrogen category. However, special attention is required for drying and storing these electrodes to prevent moisture absorption. Always follow the manufacturer’s recommendations for proper handling.)

Q6. What issues could arise when making MMA (SMAW) welds with damaged electrode coatings?

1. Porosity
2. Undercut
3. Excessive penetration
4. Excessive bead height

(Explanation: Damage electrode coating can lead to contamination and the release of gases during welding, resulting in porosity in the weld. Porosity is the formation of small cavities or voids within the weld metal, and it can weaken the weld and adversely affect its mechanical properties.)

Q7. Which defect would you expect to get in TIG welds in non-deoxidised steel?

1. Undercut
2. Porosity
3. Tungsten inclusions
4. Linear misalignment

(Explanation: In non-deoxidized steel, porosity can occur due to the presence of oxygen and other contaminants in the weld zone, leading to gas entrapment during solidification. Proper welding techniques and the use of suitable shielding gases (such as argon) are essential to minimize the risk of porosity in TIG welding.)

Q8. The static output characteristic required for MIG/MAG welding would be

1. Constant current
2. Constant voltage
3. Constant polarity
4. Constant amperage

(Explanation: A constant voltage (CV) output characteristic is typically preferred in MIG/MAG due to;

• Stable Arc: A constant voltage power source helps maintain a stable arc by providing a consistent voltage level across the welding arc.
• Wire Feed Control: With a constant voltage power source, changes in arc length do not significantly affect the current, making it easier to control the wire feed speed and, consequently, the heat input.
• Penetration Control: Constant voltage allows for better control over the penetration depth of the weld. This is important in achieving the desired weld profile and ensuring proper fusion between the base metals.

While constant current (CC) sources are suitable for SMAW, constant voltage is generally more appropriate for MIG/MAG welding due to the specific requirements of the process.)

Q9. You notice manual metal arc electrodes, stripped of flux, are being used as filler wire for TIG welding. You would object because:

1. It is too expensive
2. The wire would be too thick
3. The metal composition may be wrong
4. The wire is too short

(Explanation: Using manual metal arc electrodes stripped of flux as filler wire for TIG welding is not recommended because the composition of the filler material may not be suitable for the specific requirements of TIG welding. Manual metal arc electrodes are designed for a different welding process (shielded metal arc welding or SMAW), and their composition may not match the metallurgical needs of TIG welding. For TIG welding, it’s important to use filler materials that are specifically designed for the process and compatible with the base metal being welded.)

Q10. A common gas / mixture used in MIG welding nickel alloys to combine good levels of penetration with good arc stability would be:

1. 100 % CO2
2. 100% Argon
3. 80% Argon 20% CO2
4. 98% Argon 2% Oxygen

(Explanation: For welding nickel alloys, including those with high chromium content like Inconel, 100% argon is a common choice for shielding gas to ensure good arc stability and minimize oxidation.)

Q11. In order to calculate arc energy, it is necessary to know:

1. Current and Voltage
2. Current, Voltage, and Travel speed
3. Current , Voltage, and weave width
4. Wire feed, Voltage, and burn-off time

(Explanation: To calculate arc energy, you would typically need to know the following parameters:

• Current: The amperage or current flowing through the welding arc.
• Voltage: The electric potential difference across the welding arc.
• .Travel speed: The speed at which the welding process progresses along the joint.

Formula for arc energy is (Volts X Amps)/Travel Speed x 100. Units are; Arc energy: kjJ/mm and travel speed: mm/sec)

Q12. Which of the following weld defects is most likely to be caused by poor welding technique when using the MMA welding (SMAW) process?

1. Hydrogen Induced Cold Cracking
2. Crater cracks
3. Plate laminations
4. Copper inclusions

(Explanation: Crater cracks occur at the end of a weld bead. They are typically caused by inadequate welding techniques, such as sudden termination of the welding arc without proper crater filling.  This can result in stress concentrations and cracking in the crater region. Proper techniques, such as backstepping or ensuring complete crater fill, can help minimize the occurrence of crater cracks.)

Q13. In MMA welding (SMAW) what parameter is used to control the penetration into the base material?

1. Voltage
2. Welding speed
3. Iron powders in the coating
4. Current

(Explanation: Current plays a significant role in controlling the depth of penetration during welding. Increasing the current generally leads to greater heat input and deeper penetration, while decreasing the current can result in shallower penetration.)

Q14. For TIG welding of austenitic stainless steel pipe, why is argon gas backing employed?

1. Prevent oxidation
2. Prevent underbead cracking
3. Prevent undercut
4. None of the above

(Explanation: The argon gas creates an inert atmosphere around the weld area, shielding it from atmospheric oxygen. This is crucial because exposure to oxygen during welding can lead to oxidation, which can result in poor weld quality and a decrease in corrosion resistance.)

Q15. Which gas is the most suitable gas for GMAW for 304L and 316L stainless steel?

1. 100% Argon
2. 70% Argon + 30% He
3. Argon + 20% Hydrogen
4. Argon + 1% O2

(Explanation: Argon with 1% oxygen (Option 4) is chosen for GMAW of 304L and 316L stainless steels to enhance arc stability. The controlled addition of oxygen improves weld characteristics without causing excessive oxidation. However, for applications where oxidation is a concern, 100% Argon (Option 1) remains a suitable choice.)

Q16. Movement of the arc in MMA welding (SMAW) by magnetic forces is called:

1. Arc deviation
2. Arc misalignment
3. Arc blow
4. Arc eye

(Explanation: Arc blows in MMA welding when the welding arc is pushed or pulled due to magnetic forces, causing unwanted deviation. Adjusting electrode position and welding parameters helps control this phenomenon.)

Q17. MIG/MAG welding has a tendency to give lack of sidewall fusion when…..

1. Spray transfer condition are used
2. 100% CO2 shielding gas is used
3. Pulsed current is used
4. Dip transfer conditions are used

(Explanation: In dip transfer conditions, the welding wire is fed to the weld pool in a series of short-circuits (the wire touches the metal, melts a bit, jumps back, and repeats). This mode is often associated with lower energy input. In such conditions, achieving proper sidewall fusion can be challenging, leading to potential issues with the fusion along the sides of the weld joint.)

Q18. Why is the arc shielded when using an arc welding process ?

1. To eliminate hydrogen from the arc region
2. To exclude the atmosphere from the arc region
3. To retard the cooling rate
4. All of the above

(Explanation: The arc needs to be shielded from the surrounding atmosphere. The purpose of the shielding is to prevent the molten metal from reacting with atmospheric elements such as oxygen and nitrogen. If not shielded, it could lead to issues like oxidation, porosity, and other weld defects.)

Q19. Which of the following variables will be most affected by variations in arc length when MMA welding (SMAW)?

1. Travel speed
2. Amperage
3. Polarity
4. Voltage

(Explanation: Arc length is the distance between the tip of the welding electrode and the surface of the workpiece. As the arc length changes, the voltage will also vary. When the arc length increases, the voltage tends to increase and vice versa. This relationship is described by Ohm’s Law (V = I * R), where V is voltage, I is current (amperage), and R is the resistance of the arc. Changes in arc length affect the resistance of the arc, leading to variations in voltage.)

Q20. Which of the following defects is more common to welds deposited by CO2 welding than welds deposited by MMA?

1. Slag inclusions
2. Excess penetration
3. Lack of sidewall fusion
4. Tungsten inclusions

(In CO2 welding (GMAW with CO2 shielding gas), the welding characteristics and heat input may sometimes result in a higher likelihood of insufficient sidewall fusion compared to MMA welding. Lack of fusion in MIG welding can also be caused by poor equipment maintenance, like faulty wire feeders or worn contact tips. Incorrect settings, such as voltage or wire speed, can also lead to insufficient heat. Additionally, not cleaning between welding passes can result in issues due to spatters, or contaminants)

Q21. Which welding technique is most suitable for welding thin sheets of metal?

1. Submerged Arc Welding (SAW)
2. Gas Tungsten Arc Welding (GTAW/TIG)
3. Shielded Metal Arc Welding (SMAW/Stick)
4. Flux-Cored Arc Welding (FCAW)

(Explanation: The most suitable welding technique for welding thin sheets of metal is Gas Tungsten Arc Welding (GTAW/TIG). This method is preferred because it allows for precise control over the heat applied to the metal, which helps prevent burn-through and distortion. TIG welding uses a non-melting tungsten electrode and an inert gas to protect the weld area, resulting in clean and strong welds. Other techniques, such as stick welding and flux-cored arc welding, can be less controlled and may damage thin sheets, making TIG the ideal choice for this type of work.)

Q22. What is the primary function of a shielding gas in welding?

1. To provide light during the welding process
2. To protect the weld from atmospheric contamination
3. To cool down the welding equipment
4. To remove impurities from the base materials

(Explanation: Shielding gases play a crucial role in welding by creating an inert atmosphere around the weld area. The primary function of these gases is to prevent atmospheric gases, such as oxygen and water vapor, from coming into contact with the molten weld pool. When the weld pool is exposed to atmospheric gases, it can lead to various defects in the weld, such as:

• Oxidation: The reaction between the molten metal and oxygen in the air can cause discoloration and reduced corrosion resistance in the weld.
• Porosity: Atmospheric gases can get trapped in the solidifying weld metal, creating small cavities or pores that weaken the weld.

By shielding the weld area with an inert gas like argon or helium, the molten metal is protected from these atmospheric contaminants, ensuring a high-quality, defect-free weld.)

Q23. What’s the best way to weld thin metals without burning through?

1. Use a lower amperage setting
2. Use a shorter arc length
3. Use a backing strip
4. All of the above

(Explanation: When it comes to welding thin metals, avoiding burn-through is key! The best approach is to combine several techniques: first, using a lower amperage setting helps keep the heat in check, reducing the risk of overheating the metal. Next, keeping a shorter arc length focuses the heat right where you need it, preventing excess heat from affecting nearby areas. Finally, incorporating a backing strip can absorb some of that extra heat, giving you even more control and protection against burn-through. By using these strategies together, you can achieve clean, high-quality welds on thin materials without the hassle of common issues!)

Q24. What’s the best way to weld aluminum?

1. Use a TIG process with a pure argon shielding gas
2. Use a MIG process with a mixture of argon and helium
3. Use a stick welder with a stainless steel electrode
4. Use a SAW process with a flux designed for aluminum

(Explanation: When it comes to welding aluminum, the TIG (Tungsten Inert Gas) process with pure argon shielding gas is often considered the best method! TIG welding allows for precise control over the heat input, which is crucial for working with aluminum’s unique properties. The pure argon gas creates an inert atmosphere that protects the weld pool from contamination, ensuring clean and strong welds. While MIG welding with argon and helium can also work well for aluminum, TIG provides superior control, especially for thinner materials. Stick welding and submerged arc welding (SAW) are generally not recommended for aluminum due to their limitations in handling this lightweight metal effectively. So, for top-notch aluminum welding, go with the TIG process and pure argon!)

Q25: Which of the following is a common respiratory hazard when welding?

1. Carbon monoxide
2. Nitrogen dioxide
3. Metal fumes
4. All of the above

(Explanation: Welding produces a variety of harmful fumes and gases, including carbon monoxide, nitrogen dioxide, and metal fumes from the materials you’re working with. Breathing in these substances can cause serious respiratory problems, so it’s super important to have good ventilation and wear respiratory protection.)

Q26. What does the term “undercut” refer to in welding?

1. Excessive weld metal
2. A groove melted into the base metal next to the weld
3. A type of welding rod
4. A welding technique

(Explanation: Undercut is a welding defect where a groove is formed on the base metal along the edges of the weld. This defect can weaken the weld joint, making it less durable and reliable. Common causes of undercut include high welding current, incorrect electrode angle, fast travel speed, and improper welding techniques. To prevent undercut, welders should reduce the welding current, adjust the electrode angle to be more perpendicular to the workpiece, slow down the travel speed, and use proper welding techniques to ensure consistent movement. To learn more about welding defects, please click here.)