AWS-CWI Part- A Exam Questions answers

AWS-CWI Part- A Exam Top 50 Questions answers

Part A: Fundamentals (20 Questions)

1. What is the primary purpose of a welding procedure specification (WPS)?
   A) To certify welders
   B) To provide instructions for producing a sound weld
   C) To evaluate weld imperfections
   D) To specify nondestructive testing methods
   Answer: B
   Explanation: A WPS is a documented guide that outlines the parameters (e.g., voltage, amperage, electrode type) needed to produce a weld that meets code requirements. It ensures consistency and quality in welding.
2. Which welding process uses a non-consumable electrode?
   A) SMAW
   B) GMAW
   C) GTAW
   D) FCAW
   Answer: C
   Explanation: Gas Tungsten Arc Welding (GTAW), also known as TIG, uses a non-consumable tungsten electrode to create the arc, with filler metal added separately if needed.
3. What does the term “porosity” refer to in a weld?
   A) A crack in the weld metal
   B) Gas pockets trapped in the weld
   C) Excessive weld reinforcement
   D) Incomplete fusion between weld and base metal
   Answer: B
   Explanation: Porosity occurs when gas becomes trapped in the weld pool during solidification, forming voids or cavities that weaken the weld.
4. Which nondestructive testing (NDT) method is best for detecting surface cracks?
   A) Radiographic Testing (RT)
   B) Ultrasonic Testing (UT)
   C) Magnetic Particle Testing (MT)
   D) Visual Testing (VT)
   Answer: C
   Explanation: MT is ideal for detecting surface and near-surface cracks in ferromagnetic materials by using magnetic fields and iron particles to highlight discontinuities.
5. What is the purpose of preheating base metal before welding?
   A) To increase weld penetration
   B) To reduce residual stresses and prevent cracking
   C) To remove surface contaminants
   D) To improve electrode stability
   Answer: B
   Explanation: Preheating slows the cooling rate, reducing residual stresses and the risk of hydrogen-induced cracking, especially in high-carbon or thick materials.
6. What does the AWS designation “E7018” indicate for an electrode?
   A) 70,000 psi tensile strength, low-hydrogen coating
   B) 70,000 psi yield strength, cellulosic coating
   C) 70% iron powder in coating
   D) 18% elongation in weld metal
   Answer: A
   Explanation: E7018 is an SMAW electrode with a minimum tensile strength of 70,000 psi, low-hydrogen coating, and iron powder for improved deposition.
7. Which welding process is most susceptible to atmospheric contamination?
   A) SMAW
   B) GTAW
   C) SAW
   D) FCAW
   Answer: B
   Explanation: GTAW requires a shielding gas (e.g., argon) to protect the weld pool, making it highly sensitive to drafts or improper gas flow that can cause contamination.
8. What is the primary function of flux in submerged arc welding (SAW)?
   A) To increase welding speed
   B) To shield the arc and weld pool
   C) To clean the base metal
   D) To improve electrode conductivity
   Answer: B
   Explanation: Flux in SAW covers the arc and weld pool, protecting them from atmospheric gases and forming a slag to refine the weld metal.
9. What is a common cause of incomplete fusion in welds?
   A) Excessive welding speed
   B) Too high a preheat temperature
   C) Overly long arc length
   D) Excessive electrode diameter
   Answer: A
   Explanation: Excessive welding speed prevents adequate heat input, leading to poor fusion between the weld metal and base material or between weld passes.
10. What does “heat-affected zone” (HAZ) refer to?
    A) The melted portion of the weld
    B) The base metal altered by welding heat
    C) The slag covering the weld
    D) The electrode coating residue
    Answer: B
    Explanation: The HAZ is the area of base metal that undergoes microstructural changes due to welding heat but does not melt, affecting its mechanical properties.
11. Which standard governs welding symbols in the United States?
    A) AWS A2.4
    B) AWS D1.1
    C) ASME Section IX
    D) API 1104
    Answer: A
    Explanation: AWS A2.4 provides the standard for welding symbols, detailing how to represent welds, dimensions, and processes on drawings.
12. What is the primary advantage of ultrasonic testing (UT)?
    A) Low equipment cost
    B) Ability to detect internal defects
    C) No need for surface preparation
    D) Suitability for non-metallic materials
    Answer: B
    Explanation: UT uses high-frequency sound waves to detect internal defects like cracks or voids, making it effective for volumetric inspection.
13. What is a common safety hazard in arc welding?
    A) Excessive noise
    B) Ultraviolet (UV) radiation
    C) Low voltage exposure
    D) Non-ionizing radiation
    Answer: B
    Explanation: Arc welding produces UV radiation, which can cause burns (arc flash) or eye damage (welder’s flash) without proper PPE like helmets and gloves.
14. What does “backing” refer to in welding?
    A) A material placed behind the weld to support molten metal
    B) The final weld pass
    C) The electrode coating
    D) A preheat treatment
    Answer: A
    Explanation: Backing (e.g., ceramic or copper strips) supports the weld pool during root pass welding, ensuring complete penetration and preventing burn-through.
15. Which gas is commonly used as a shield in GMAW for steel?
    A) Argon
    B) Helium
    C) Carbon dioxide
    D) Nitrogen
    Answer: C
    Explanation: Carbon dioxide or CO2-argon mixtures are commonly used in GMAW for steel due to cost-effectiveness and good penetration characteristics.
16. What is the significance of a welder qualification test?
    A) To certify a welding machine
    B) To verify a welder’s ability to produce sound welds
    C) To develop a WPS
    D) To inspect weld imperfections
    Answer: B
    Explanation: Welder qualification tests ensure a welder can follow a WPS and produce welds that meet code requirements for quality and strength.
17. What defect is caused by rapid cooling of the weld pool?
    A) Porosity
    B) Cracking
    C) Slag inclusion
    D) Incomplete fusion
    Answer: B
    Explanation: Rapid cooling increases residual stresses and can cause hydrogen-induced or solidification cracking, especially in susceptible materials.
18. What does the term “duty cycle” mean for a welding machine?
    A) The percentage of time it can operate at a given output
    B) The maximum welding speed
    C) The electrode consumption rate
    D) The time to complete a weld pass
    Answer: A
    Explanation: Duty cycle indicates how long a machine can weld at a specific amperage before needing to cool down (e.g., 60% at 200A means 6 minutes out of 10).
19. What is the purpose of a liquid penetrant test (PT)?
    A) To detect internal voids
    B) To measure weld hardness
    C) To identify surface-breaking defects
    D) To evaluate base metal composition
    Answer: C
    Explanation: PT involves applying a dye to reveal surface cracks or porosity visible under UV or white light, ideal for non-ferromagnetic materials.
20. What is a key factor in controlling weld distortion?
    A) Increasing welding speed
    B) Using a larger electrode
    C) Minimizing heat input
    D) Applying post-weld heat treatment
    Answer: C
    Explanation: Minimizing heat input reduces thermal expansion and contraction, helping control distortion in the weld and base metal.

Part B: Practical (15 Questions)

21. When measuring a fillet weld with a fillet weld gauge, what dimension is typically checked?
    A) Weld reinforcement
    B) Leg length
    C) Throat thickness
    D) Weld width
    Answer: B
    Explanation: Fillet weld gauges measure leg length, the distance from the weld toe to the root along the base metal, to verify it meets specifications.
22. A weld replica shows a crack. What is the appropriate action per AWS D1.1?
    A) Accept the weld if the crack is small
    B) Reject the weld
    C) Measure the crack depth
    D) Apply additional weld passes
    Answer: B
    Explanation: AWS D1.1 prohibits cracks in welds, regardless of size, due to their potential to propagate and cause failure.
23. What tool is used to measure the depth of undercut?
    A) Fillet weld gauge
    B) Bridge cam gauge
    C) Micrometer
    D) Magnifying glass
    Answer: B
    Explanation: A bridge cam gauge measures undercut depth, weld reinforcement, and other weld dimensions accurately in a practical inspection.
24. A fillet weld is specified as 6 mm. Your measurement shows 5 mm. Is it acceptable if the tolerance is ±1 mm?
    A) Yes
    B) No
    C) Only if approved by the engineer
    D) Only if the weld is visually acceptable
    Answer: A
    Explanation: A 5 mm weld falls within the tolerance range (5–7 mm), so it meets the specification.
25. What imperfection is indicated by a rough, uneven weld surface?
    A) Porosity
    B) Arc strikes
    C) Weld ripple
    D) Spatter
    Answer: C
    Explanation: Weld ripple refers to the uneven surface texture of a weld bead, often due to inconsistent welding technique, and may require evaluation per code.
26. When inspecting a weld replica, you notice excess reinforcement. What should you check?
    A) Weld length
    B) Code acceptance criteria
    C) Electrode type
    D) Welder qualification
    Answer: B
    Explanation: Excess reinforcement must be compared to code limits (e.g., AWS D1.1 specifies maximum reinforcement heights) to determine acceptability.
27. What does a V-groove gauge measure in a butt weld?
    A) Weld reinforcement
    B) Groove angle
    C) Root opening
    D) Weld throat
    Answer: B
    Explanation: A V-groove gauge checks the bevel or groove angle in a prepared joint to ensure it matches the WPS requirements.
28. A weld is rejected for excessive porosity. What measurement is critical?
    A) Weld length
    B) Pore size and distribution
    C) Weld reinforcement height
    D) Leg length
    Answer: B
    Explanation: AWS D1.1 specifies limits on pore size and spacing (e.g., maximum diameter or cumulative length), which determine if porosity is acceptable.
29. What indicates incomplete penetration in a butt weld replica?
    A) Lack of fusion at the weld root
    B) Excess weld metal at the surface
    C) Surface cracks
    D) Slag inclusions
    Answer: A
    Explanation: Incomplete penetration occurs when the weld metal does not fully penetrate the joint root, often visible in replicas or radiographs.
30. You measure a fillet weld’s throat thickness as undersized. What does this affect?
    A) Weld strength
    B) Weld length
    C) Weld appearance
    D) Electrode efficiency
    Answer: A
    Explanation: The throat thickness determines the load-carrying capacity of a fillet weld, and an undersized throat reduces its strength.
31. What is the purpose of a magnifying glass in weld inspection?
    A) To measure weld dimensions
    B) To detect fine surface imperfections
    C) To evaluate weld color
    D) To check electrode coating
    Answer: B
    Explanation: A magnifying glass (e.g., 10x) helps identify small cracks, porosity, or inclusions not visible to the naked eye.
32. A weld replica shows slag inclusions. What caused this?
    A) Improper cleaning between passes
    B) Excessive welding speed
    C) Low amperage
    D) Incorrect shielding gas
    Answer: A
    Explanation: Slag inclusions occur when slag from previous passes is not removed, becoming trapped in the weld metal.
33. When using a caliper to measure a weld, what dimension is it best suited for?
    A) Weld reinforcement
    B) Weld ripple
    C) Arc strike length
    D) Weld porosity
    Answer: A
    Explanation: Calipers provide precise measurements of weld reinforcement, leg length, or other external dimensions.
34. A butt weld shows arc strikes outside the weld zone. Why is this a concern?
    A) It reduces weld strength
    B) It may initiate cracks
    C) It affects weld appearance only
    D) It violates WPS requirements
    Answer: B
    Explanation: Arc strikes can create stress risers or microcracks in the base metal, potentially leading to failure under load.
35. What does a fillet weld gauge confirm about convexity?
    A) Weld length
    B) Weld profile acceptability
    C) Weld penetration
    D) Weld hardness
    Answer: B
    Explanation: A fillet weld gauge checks if convexity (outward curvature) is within code limits to ensure proper weld profile and strength.

Part C: Code Book – AWS D1.1 (15 Questions)

36. Per AWS D1.1, what is the maximum allowable depth of undercut for statically loaded structures?
    A) 0.5 mm
    B) 1.0 mm
    C) 1.5 mm
    D) 2.0 mm
    Answer: B
    Explanation: AWS D1.1, Clause 6, specifies undercut must not exceed 1 mm for statically loaded structures to ensure structural integrity.
37. What is the minimum preheat temperature for welding 50 mm thick A36 steel per AWS D1.1?
    A) 10°C
    B) 66°C
    C) 107°C
    D) 150°C
    Answer: B
    Explanation: AWS D1.1 Table 3.2 requires a minimum preheat of 66°C for A36 steel over 25 mm but less than 65 mm thick.
38. Per AWS D1.1, what is the maximum allowable single pore diameter in a fillet weld?
    A) 1 mm
    B) 2 mm
    C) 3 mm
    D) 4 mm
    Answer: B
    Explanation: AWS D1.1 Clause 6 limits single pore diameter to 2 mm or 1/3 of the weld size, whichever is smaller, for fillet welds.
39. What is required if a welder’s qualification test weld fails per AWS D1.1?
    A) Immediate retest with no additional training
    B) Training followed by retest
    C) Permanent disqualification
    D) Engineer approval to continue
    Answer: B
    Explanation: AWS D1.1 Clause 4 requires additional training before retesting a welder who fails a qualification test.
40. Per AWS D1.1, what is the maximum allowable weld reinforcement for a butt weld?
    A) 1 mm
    B) 3 mm
    C) 5 mm
    D) 7 mm
    Answer: B
    Explanation: AWS D1.1 Table 6.1 specifies a maximum reinforcement of 3 mm for butt welds to ensure a smooth transition and avoid stress concentration.
41. What is the required frequency of visual inspection per AWS D1.1?
    A) Before, during, and after welding
    B) Only after welding
    C) Only before welding
    D) Once per shift
    Answer: A
    Explanation: AWS D1.1 Clause 6 mandates visual inspection at all stages—before (joint prep), during (welding technique), and after (final weld)—to ensure quality.
42. Per AWS D1.1, what is the acceptance criterion for a fillet weld’s convexity?
    A) Convexity must not exceed 2 mm
    B) Convexity must not exceed 0.1 times weld size + 3 mm
    C) No convexity is allowed
    D) Convexity is unlimited
    Answer: B
    Explanation: AWS D1.1 Table 6.1 limits convexity to 0.1 times the weld size plus 3 mm to maintain proper weld profile.
43. What is the minimum length of a welder qualification test weld per AWS D1.1?
    A) 100 mm
    B) 150 mm
    C) 200 mm
    D) 300 mm
    Answer: B
    Explanation: AWS D1.1 Clause 4 requires a minimum test weld length of 150 mm for plate to ensure adequate evaluation of welder skill.
44. Per AWS D1.1, what is the maximum allowable crack length in a weld?
    A) 1 mm
    B) 2 mm
    C) 3 mm
    D) None allowed
    Answer: D
    Explanation: AWS D1.1 Clause 6 prohibits all cracks in welds due to their potential to propagate and cause catastrophic failure.
45. What is the required electrode storage condition per AWS D1.1 for low-hydrogen electrodes?
    A) Store at room temperature
    B) Keep in a dry, heated oven at 120°C
    C) Submerge in water
    D) Store in open air
    Answer: B
    Explanation: AWS D1.1 Clause 5 requires low-hydrogen electrodes (e.g., E7018) to be stored in a heated oven at 120°C or higher to prevent moisture absorption.
46. Per AWS D1.1, what is the maximum allowable mismatch (high-low) for a butt joint?
    A) 1 mm
    B) 2 mm
    C) 3 mm
    D) 4 mm
    Answer: C
    Explanation: AWS D1.1 Table 5.4 allows a maximum mismatch of 3 mm for butt joints to ensure proper load transfer.
47. What NDT method is required for critical welds per AWS D1.1?
    A) Visual Testing only
    B) Radiographic or Ultrasonic Testing
    C) Liquid Penetrant Testing
    D) Magnetic Particle Testing
    Answer: B
    Explanation: AWS D1.1 Clause 6 specifies RT or UT for critical welds (e.g., complete joint penetration welds) to detect internal defects.
48. Per AWS D1.1, what is the maximum allowable slag inclusion length in a weld?
    A) 2 mm
    B) 3 mm
    C) 6 mm
    D) 10 mm
    Answer: C
    Explanation: AWS D1.1 Table 6.1 permits slag inclusions up to 6 mm in length, depending on weld thickness and type.
49. What is the required interpass temperature range for welding per AWS D1.1?
    A) Same as preheat temperature
    B) Below 100°C
    C) Above 200°C
    D) No limit specified
    Answer: A
    Explanation: AWS D1.1 Clause 5 requires the interpass temperature to be at least the minimum preheat temperature to control cooling rates.
50. Per AWS D1.1, who is responsible for approving a WPS?
    A) The welder
    B) The welding inspector
    C) The engineer
    D) The NDT technician
    Answer: C
    Explanation: AWS D1.1 Clause 4 assigns the engineer the responsibility for approving the WPS to ensure it meets design and code requirements.