CWB Level 2 Welding Inspector Practice
Exam Study Guide | Complete Actual and
Verified Exam Questions with Correct
Answers and Detailed Rationales | Updated
for 2026/2027 | Already Graded A+
EXAM OVERVIEW
Category Details
Exam Format Multiple-choice and short-answer questions
Content Areas Welding Power Sources, Electrodes & Consumables,
Metallurgy, NDT Methods (PT, MT, RT, UT), Inspection
Procedures, Standards
Governing CSA W178.2, CSA W59, ASME Section IX, CGSB
Standards
Total 220
Questions
SECTION 1: ELECTRICAL & WELDING POWER SOURCES
Questions 1-25
Question 1
In parallel electrical circuits, the voltage across each resistor is the same since each
path is connected to the same voltage source. Select the correct statement.
A. In each parallel path the resistance must be equalized to create equal voltage.
B. The current flowing in each parallel path must be the same as the voltage.
C. The current flowing in each parallel path depends on the resistance in each path.
pg. 1
,D. The current flowing in each parallel path depends on the capacitance in each
path.
Answer: C
Rationale: In a parallel circuit, voltage is constant across each branch, but current
in each branch is determined by that branch's resistance according to Ohm's law (I
= V/R).
Question 2
The duty cycle of a welding power supply is based upon delivering its rated output
for a given number of minutes. Which statement is correct?
A. A 300 amp/60% duty cycle machine is rated to deliver 300 amps for 6 minutes
in a ten minute period.
B. A 300 amp/30% duty cycle machine is rated to deliver 300 amps in a ten minute
period.
C. A 250 amp/30% duty cycle machine is rated to deliver 250 amps for 30 minutes
separated by 10 minutes at rest.
D. A 300 amp/60% duty cycle machine is rated to deliver 500 amps maximum for
6 minutes in a ten minute period.
Answer: A
Rationale: Duty cycle is the percentage of a 10-minute period that a machine can
operate at rated output. 60% = 6 minutes welding, 4 minutes cooling.
Question 3
Conventional transformer-rectifiers:
A. Convert direct current into alternating current.
B. Convert alternating current into direct current.
C. Convert alternating current into pulsed current.
D. Convert direct current into pulsed current.
Answer: B
pg. 2
,Rationale: A transformer-rectifier takes AC input, steps voltage up/down, then
rectifies AC to DC.
Question 4
A conventional diode allows current in one direction only. A silicon controlled
rectifier (SCR) operates differently. How does it work?
A. An SCR conducts current in both directions until turned on.
B. An SCR is non-conductive until turned on and then allows current in both
directions.
C. An SCR is non-conductive until turned on, allowing current in one direction
only until current stops.
Answer: C
Rationale: An SCR is triggered by a gate pulse and conducts in one direction only
until current drops below holding current.
Question 5
What is the term for voltage measured across the output terminals of a welding
machine when no current is being drawn?
A. Diode voltage
B. Operating voltage
C. Open circuit voltage
D. Terminal voltage
Answer: C
Rationale: Open circuit voltage (OCV) is the voltage available to strike the arc
when no current is flowing.
Question 6
One of the simplest ways of controlling the output of a welding transformer is to
change the efficiency of coupling between the primary and secondary coils. How
can this be done?
pg. 3
, A. Slide a piece of wood between the primary and secondary coils.
B. Design the transformer with either a moving core or moving primary coils.
C. Design the transformer with a number of taps to select different output curves.
D. Use timed firing of SCR's to control total conduction time.
Answer: B
Rationale: Moving the core or primary coils changes magnetic coupling, varying
output voltage and current.
Question 7
When choosing between AC and DC output:
A. The process generally determines the type of current.
B. High current output machines are always both AC/DC.
C. DC is generally used for very high output applications.
D. Most supplies are equipped with constant voltage/constant current options.
Answer: A
Rationale: The welding process and material determine polarity and current type
required.
Question 8
Which metal has the lowest electrical resistivity?
A. Aluminum
B. Tungsten
C. Copper
D. Iron
Answer: C
Rationale: Copper has the lowest electrical resistivity among common metals,
making it an excellent conductor.
pg. 4
Exam Study Guide | Complete Actual and
Verified Exam Questions with Correct
Answers and Detailed Rationales | Updated
for 2026/2027 | Already Graded A+
EXAM OVERVIEW
Category Details
Exam Format Multiple-choice and short-answer questions
Content Areas Welding Power Sources, Electrodes & Consumables,
Metallurgy, NDT Methods (PT, MT, RT, UT), Inspection
Procedures, Standards
Governing CSA W178.2, CSA W59, ASME Section IX, CGSB
Standards
Total 220
Questions
SECTION 1: ELECTRICAL & WELDING POWER SOURCES
Questions 1-25
Question 1
In parallel electrical circuits, the voltage across each resistor is the same since each
path is connected to the same voltage source. Select the correct statement.
A. In each parallel path the resistance must be equalized to create equal voltage.
B. The current flowing in each parallel path must be the same as the voltage.
C. The current flowing in each parallel path depends on the resistance in each path.
pg. 1
,D. The current flowing in each parallel path depends on the capacitance in each
path.
Answer: C
Rationale: In a parallel circuit, voltage is constant across each branch, but current
in each branch is determined by that branch's resistance according to Ohm's law (I
= V/R).
Question 2
The duty cycle of a welding power supply is based upon delivering its rated output
for a given number of minutes. Which statement is correct?
A. A 300 amp/60% duty cycle machine is rated to deliver 300 amps for 6 minutes
in a ten minute period.
B. A 300 amp/30% duty cycle machine is rated to deliver 300 amps in a ten minute
period.
C. A 250 amp/30% duty cycle machine is rated to deliver 250 amps for 30 minutes
separated by 10 minutes at rest.
D. A 300 amp/60% duty cycle machine is rated to deliver 500 amps maximum for
6 minutes in a ten minute period.
Answer: A
Rationale: Duty cycle is the percentage of a 10-minute period that a machine can
operate at rated output. 60% = 6 minutes welding, 4 minutes cooling.
Question 3
Conventional transformer-rectifiers:
A. Convert direct current into alternating current.
B. Convert alternating current into direct current.
C. Convert alternating current into pulsed current.
D. Convert direct current into pulsed current.
Answer: B
pg. 2
,Rationale: A transformer-rectifier takes AC input, steps voltage up/down, then
rectifies AC to DC.
Question 4
A conventional diode allows current in one direction only. A silicon controlled
rectifier (SCR) operates differently. How does it work?
A. An SCR conducts current in both directions until turned on.
B. An SCR is non-conductive until turned on and then allows current in both
directions.
C. An SCR is non-conductive until turned on, allowing current in one direction
only until current stops.
Answer: C
Rationale: An SCR is triggered by a gate pulse and conducts in one direction only
until current drops below holding current.
Question 5
What is the term for voltage measured across the output terminals of a welding
machine when no current is being drawn?
A. Diode voltage
B. Operating voltage
C. Open circuit voltage
D. Terminal voltage
Answer: C
Rationale: Open circuit voltage (OCV) is the voltage available to strike the arc
when no current is flowing.
Question 6
One of the simplest ways of controlling the output of a welding transformer is to
change the efficiency of coupling between the primary and secondary coils. How
can this be done?
pg. 3
, A. Slide a piece of wood between the primary and secondary coils.
B. Design the transformer with either a moving core or moving primary coils.
C. Design the transformer with a number of taps to select different output curves.
D. Use timed firing of SCR's to control total conduction time.
Answer: B
Rationale: Moving the core or primary coils changes magnetic coupling, varying
output voltage and current.
Question 7
When choosing between AC and DC output:
A. The process generally determines the type of current.
B. High current output machines are always both AC/DC.
C. DC is generally used for very high output applications.
D. Most supplies are equipped with constant voltage/constant current options.
Answer: A
Rationale: The welding process and material determine polarity and current type
required.
Question 8
Which metal has the lowest electrical resistivity?
A. Aluminum
B. Tungsten
C. Copper
D. Iron
Answer: C
Rationale: Copper has the lowest electrical resistivity among common metals,
making it an excellent conductor.
pg. 4
