CWB WELDING INSPECTOR EXAM
PREP (2026/2027) COMPREHENSIVE
ASSESSMENT QUESTIONS AND
ANSWERS
1. Which of the following describes the ‘Rectifier’ component in a modern welding power
source?
A. It increases the voltage and decreases the amperage for safer welding.
B. It stores electrical energy to provide a high-frequency start.
C. It converts alternating current (AC) into direct current (DC).
D. It prevents the arc from blowing out in windy conditions.
Answer: C
Conceptual Explanation: In welding power sources, rectifiers are electrical devices that
allow current to flow in one direction only, effectively converting AC from the transformer
into DC.
,2. Under CSA W59, what is the maximum permissible undercut for a statically loaded
structure in material less than 16mm thick?
A. 1.0 mm (0.04 in)
B. 0.25 mm (0.01 in)
C. 1.5 mm (0.06 in)
D. 2.0 mm (0.08 in)
Answer: A
Conceptual Explanation: For statically loaded structures, CSA W59 generally allows an
undercut up to 1mm (1/32 inch) for most applications, provided it does not reduce the
thickness below design requirements.
3. In the SMAW electrode designation ‘E4918-1’, what does the number ‘1’ specifically
indicate?
A. The electrode can only be used in the flat position.
B. The electrode has improved toughness (impact properties).
C. The electrode uses an acidic flux coating.
D. The electrode is intended for single-pass welding only.
Answer: B
Conceptual Explanation: The suffix ‘-1’ in the CSA/AWS classification indicates that the
electrode meets specific requirements for improved ductility and notch toughness.
, 4. What is the primary cause of ‘hydrogen-induced cold cracking’ (HICC) in high-strength steel
welds?
A. High levels of nitrogen in the shielding gas.
B. Excessive welding current and travel speed.
C. Presence of moisture, high stress, and a susceptible microstructure.
D. The use of argon-CO2 mixed gases in GMAW.
Answer: C
Conceptual Explanation: HICC requires three factors: a susceptible microstructure
(martensite), a source of hydrogen (like moisture), and high residual or applied stress.
5. Which NDT method is most effective for detecting subsurface planar defects, such as lack
of side-wall fusion, in thick heavy-wall pressure vessels?
A. Liquid Penetrant Testing (PT)
B. Ultrasonic Testing (UT)
C. Magnetic Particle Testing (MT)
D. Visual Inspection (VT)
Answer: B
Conceptual Explanation: Ultrasonic Testing (UT) uses high-frequency sound waves and is
highly sensitive to planar defects regardless of their orientation, making it superior for
subsurface fusion issues.
PREP (2026/2027) COMPREHENSIVE
ASSESSMENT QUESTIONS AND
ANSWERS
1. Which of the following describes the ‘Rectifier’ component in a modern welding power
source?
A. It increases the voltage and decreases the amperage for safer welding.
B. It stores electrical energy to provide a high-frequency start.
C. It converts alternating current (AC) into direct current (DC).
D. It prevents the arc from blowing out in windy conditions.
Answer: C
Conceptual Explanation: In welding power sources, rectifiers are electrical devices that
allow current to flow in one direction only, effectively converting AC from the transformer
into DC.
,2. Under CSA W59, what is the maximum permissible undercut for a statically loaded
structure in material less than 16mm thick?
A. 1.0 mm (0.04 in)
B. 0.25 mm (0.01 in)
C. 1.5 mm (0.06 in)
D. 2.0 mm (0.08 in)
Answer: A
Conceptual Explanation: For statically loaded structures, CSA W59 generally allows an
undercut up to 1mm (1/32 inch) for most applications, provided it does not reduce the
thickness below design requirements.
3. In the SMAW electrode designation ‘E4918-1’, what does the number ‘1’ specifically
indicate?
A. The electrode can only be used in the flat position.
B. The electrode has improved toughness (impact properties).
C. The electrode uses an acidic flux coating.
D. The electrode is intended for single-pass welding only.
Answer: B
Conceptual Explanation: The suffix ‘-1’ in the CSA/AWS classification indicates that the
electrode meets specific requirements for improved ductility and notch toughness.
, 4. What is the primary cause of ‘hydrogen-induced cold cracking’ (HICC) in high-strength steel
welds?
A. High levels of nitrogen in the shielding gas.
B. Excessive welding current and travel speed.
C. Presence of moisture, high stress, and a susceptible microstructure.
D. The use of argon-CO2 mixed gases in GMAW.
Answer: C
Conceptual Explanation: HICC requires three factors: a susceptible microstructure
(martensite), a source of hydrogen (like moisture), and high residual or applied stress.
5. Which NDT method is most effective for detecting subsurface planar defects, such as lack
of side-wall fusion, in thick heavy-wall pressure vessels?
A. Liquid Penetrant Testing (PT)
B. Ultrasonic Testing (UT)
C. Magnetic Particle Testing (MT)
D. Visual Inspection (VT)
Answer: B
Conceptual Explanation: Ultrasonic Testing (UT) uses high-frequency sound waves and is
highly sensitive to planar defects regardless of their orientation, making it superior for
subsurface fusion issues.
