CWB Level 2 Welding Inspector Exam
150 Practice Questions with Rationales
Aligned with CSA W178.2 and 2026/2027 Standards
SECTION 1: WELDING PROCESSES & EQUIPMENT (Questions 1-30)
1. Which type of welding power source provides a constant current (CC) output
that is independent of voltage variations?
A. Inverter power source
B. Transformer-rectifier (CR)
C. Constant voltage (CV) inverter
D. Pulsed-GMAW power source
Answer: B
Rationale: Transformer-rectifier (CR) units are designed to deliver a constant current
output, making them ideal for processes such as SMAW and FCAW where current stability
is required to maintain consistent arc characteristics regardless of voltage fluctuations .
2. In GMAW, what is the primary effect of increasing the shielding gas flow rate
significantly beyond the recommended level?
A. Increased penetration depth
B. Reduced spatter formation
C. Dilution of the weld metal
D. Turbulence leading to porosity
Answer: D
,Rationale: Excessive gas flow creates turbulence in the weld pool and arc zone, which can
draw atmospheric gases into the weld and cause porosity. Proper flow rates must be
maintained to provide adequate shielding without inducing turbulence .
3. Which GMAW metal transfer mode uses a high peak current followed by a low
background current to improve bead shape and reduce heat input?
A. Spray transfer
B. Globular transfer
C. Pulsed transfer
D. Short-circuit transfer
Answer: C
Rationale: Pulsed GMAW alternates between a high peak current (for metal transfer) and
a low background current (to control heat input), producing a stable arc and better bead
geometry with reduced spatter compared to other modes .
4. In FCAW, what distinguishes a self-shielded (FCAW-SS) wire from a gas-shielded
(FCAW-G) wire?
A. Presence of a flux core that generates shielding gas
B. Requirement for external shielding gas
C. Higher deposition rates only in FCAW-G
D. Ability to weld stainless steel only with FCAW-SS
Answer: A
Rationale: Self-shielded FCAW wires contain a flux core that decomposes during welding
to produce shielding gases and slag, eliminating the need for external shielding gas. This
makes them suitable for outdoor applications where wind might disrupt gas shielding .
5. In SAW, the primary source of heat is:
A. Electrical resistance of the filler wire
,B. Arc produced between the electrode and workpiece
C. Focused laser beam
D. Friction between workpieces
Answer: B
Rationale: Submerged Arc Welding uses a continuously fed consumable electrode and a
non-consumable copper electrode to generate a deep, concentrated arc beneath the flux
cover. The heat from the arc melts the base metal and filler wire .
6. Which parameter most directly influences the penetration depth in electroslag
welding (ESW)?
A. Electrode diameter
B. Slag viscosity
C. Current level
D. Travel speed of the electrode
Answer: C
Rationale: In ESW, the heat generated is proportional to the welding current; higher
current increases the molten slag temperature and therefore penetration depth. Proper
current control is essential for achieving desired joint penetration .
7. In resistance welding, the heat generated at the interface is primarily a function
of:
A. Voltage × time
B. Current² × resistance × time
C. Current × voltage × resistance
D. Power density only
Answer: B
Rationale: Joule heating (I²R) at the contact surfaces produces the heat necessary for
joining in resistance welding. The heat generated is proportional to the square of the
current, the resistance of the workpieces, and the duration of current flow .
, 8. Which shielding gas has the highest ionization potential, thus improving arc
stability in GMAW?
A. Argon
B. Helium
C. CO₂
D. Nitrogen
Answer: B
Rationale: Helium has a higher ionization potential than argon, resulting in a hotter, more
stable arc. This makes it especially useful for welding thick sections where higher heat
input is beneficial, though it requires higher voltage settings .
9. Increasing the wire feed speed in GMAW while keeping voltage constant will:
A. Decrease current and reduce deposition rate
B. Increase current, raising heat input and deposition rate
C. Have no effect on current
D. Reduce arc length and cause spatter
Answer: B
Rationale: Wire feed speed is directly proportional to current in constant-voltage GMAW
systems; higher feed speed raises current and thus heat input and deposition rate. This
relationship is fundamental to understanding process control in GMAW .
10. In GTAW, what is the effect of using AC on a weld of aluminum?
A. AC provides a cleaning action through cathodic cleaning
B. AC reduces heat input compared to DC
C. AC eliminates the need for shielding gas
D. AC causes excessive oxidation of the tungsten electrode
Answer: A
150 Practice Questions with Rationales
Aligned with CSA W178.2 and 2026/2027 Standards
SECTION 1: WELDING PROCESSES & EQUIPMENT (Questions 1-30)
1. Which type of welding power source provides a constant current (CC) output
that is independent of voltage variations?
A. Inverter power source
B. Transformer-rectifier (CR)
C. Constant voltage (CV) inverter
D. Pulsed-GMAW power source
Answer: B
Rationale: Transformer-rectifier (CR) units are designed to deliver a constant current
output, making them ideal for processes such as SMAW and FCAW where current stability
is required to maintain consistent arc characteristics regardless of voltage fluctuations .
2. In GMAW, what is the primary effect of increasing the shielding gas flow rate
significantly beyond the recommended level?
A. Increased penetration depth
B. Reduced spatter formation
C. Dilution of the weld metal
D. Turbulence leading to porosity
Answer: D
,Rationale: Excessive gas flow creates turbulence in the weld pool and arc zone, which can
draw atmospheric gases into the weld and cause porosity. Proper flow rates must be
maintained to provide adequate shielding without inducing turbulence .
3. Which GMAW metal transfer mode uses a high peak current followed by a low
background current to improve bead shape and reduce heat input?
A. Spray transfer
B. Globular transfer
C. Pulsed transfer
D. Short-circuit transfer
Answer: C
Rationale: Pulsed GMAW alternates between a high peak current (for metal transfer) and
a low background current (to control heat input), producing a stable arc and better bead
geometry with reduced spatter compared to other modes .
4. In FCAW, what distinguishes a self-shielded (FCAW-SS) wire from a gas-shielded
(FCAW-G) wire?
A. Presence of a flux core that generates shielding gas
B. Requirement for external shielding gas
C. Higher deposition rates only in FCAW-G
D. Ability to weld stainless steel only with FCAW-SS
Answer: A
Rationale: Self-shielded FCAW wires contain a flux core that decomposes during welding
to produce shielding gases and slag, eliminating the need for external shielding gas. This
makes them suitable for outdoor applications where wind might disrupt gas shielding .
5. In SAW, the primary source of heat is:
A. Electrical resistance of the filler wire
,B. Arc produced between the electrode and workpiece
C. Focused laser beam
D. Friction between workpieces
Answer: B
Rationale: Submerged Arc Welding uses a continuously fed consumable electrode and a
non-consumable copper electrode to generate a deep, concentrated arc beneath the flux
cover. The heat from the arc melts the base metal and filler wire .
6. Which parameter most directly influences the penetration depth in electroslag
welding (ESW)?
A. Electrode diameter
B. Slag viscosity
C. Current level
D. Travel speed of the electrode
Answer: C
Rationale: In ESW, the heat generated is proportional to the welding current; higher
current increases the molten slag temperature and therefore penetration depth. Proper
current control is essential for achieving desired joint penetration .
7. In resistance welding, the heat generated at the interface is primarily a function
of:
A. Voltage × time
B. Current² × resistance × time
C. Current × voltage × resistance
D. Power density only
Answer: B
Rationale: Joule heating (I²R) at the contact surfaces produces the heat necessary for
joining in resistance welding. The heat generated is proportional to the square of the
current, the resistance of the workpieces, and the duration of current flow .
, 8. Which shielding gas has the highest ionization potential, thus improving arc
stability in GMAW?
A. Argon
B. Helium
C. CO₂
D. Nitrogen
Answer: B
Rationale: Helium has a higher ionization potential than argon, resulting in a hotter, more
stable arc. This makes it especially useful for welding thick sections where higher heat
input is beneficial, though it requires higher voltage settings .
9. Increasing the wire feed speed in GMAW while keeping voltage constant will:
A. Decrease current and reduce deposition rate
B. Increase current, raising heat input and deposition rate
C. Have no effect on current
D. Reduce arc length and cause spatter
Answer: B
Rationale: Wire feed speed is directly proportional to current in constant-voltage GMAW
systems; higher feed speed raises current and thus heat input and deposition rate. This
relationship is fundamental to understanding process control in GMAW .
10. In GTAW, what is the effect of using AC on a weld of aluminum?
A. AC provides a cleaning action through cathodic cleaning
B. AC reduces heat input compared to DC
C. AC eliminates the need for shielding gas
D. AC causes excessive oxidation of the tungsten electrode
Answer: A
