CO Welding Contractor Exam Questions
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
Download Pdf
1. Which welding process uses a continuously fed consumable wire
electrode and shielding gas to create an arc?
A. Shielded metal arc welding (SMAW)
B. Gas tungsten arc welding (GTAW)
C. Gas metal arc welding (GMAW)
D. Oxyfuel welding
Rationale: GMAW uses a continuously supplied wire electrode that
serves as both the electrode and, depending on the application, the
filler metal. Shielding gas protects the molten weld pool from
atmospheric contamination.
2. What is the primary purpose of shielding gas during arc welding?
,A. Increase the hardness of the base metal
B. Prevent atmospheric gases from contaminating the weld pool
C. Cool the electrode
D. Increase the electrical resistance of the circuit
Rationale: Oxygen, nitrogen, and moisture from the atmosphere can
cause porosity, embrittlement, oxidation, and other weld defects.
Shielding gas displaces atmospheric gases around the arc and molten
metal.
3. In SMAW, what component provides the filler metal for the weld?
A. Tungsten electrode
B. Shielding-gas nozzle
C. Consumable coated electrode
D. Copper backing bar
Rationale: SMAW electrodes are consumable. Their metal core
supplies filler metal while the coating produces shielding gases and
slag that protect the weld as it solidifies.
4. What is the function of welding slag?
A. Increase the welding machine voltage
B. Protect the molten and cooling weld metal from atmospheric
contamination
,C. Prevent current from flowing through the electrode
D. Replace the need for a welding helmet
Rationale: Slag forms over the weld bead and shields the hot metal
from the atmosphere. It must generally be removed between passes
when required to prevent inclusions and other defects.
5. Which welding process normally uses a nonconsumable tungsten
electrode?
A. SMAW
B. GMAW
C. FCAW
D. GTAW
Rationale: GTAW, commonly called TIG welding, uses a
nonconsumable tungsten electrode to establish the arc. Filler metal
may be added separately when required.
6. What does FCAW stand for?
A. Flux-cored aluminum welding
B. Flux-cored arc welding
C. Forced-current arc welding
D. Fusion-controlled arc welding
, Rationale: FCAW is Flux-Cored Arc Welding. It uses a tubular electrode
containing flux. Depending on the electrode type, shielding may come
from the flux, an external shielding gas, or both.
7. What is the purpose of a welding procedure specification (WPS)?
A. Establish employee vacation schedules
B. Determine the contractor's insurance premium
C. Specify the qualified variables and requirements for producing a
weld
D. Replace all welding inspection requirements
Rationale: A WPS provides controlled welding parameters and
essential requirements such as process, materials, electrode or filler
metal, preheat, interpass temperature, and electrical settings as
applicable.
8. What is preheating primarily intended to accomplish when
welding steel?
A. Make the electrode nonconductive
B. Reduce the cooling rate and help minimize cracking
C. Eliminate the need for shielding
D. Increase atmospheric humidity
and Correct Answers (Verified Answers)
Plus Rationale 2027 Q&A| Instant
Download Pdf
1. Which welding process uses a continuously fed consumable wire
electrode and shielding gas to create an arc?
A. Shielded metal arc welding (SMAW)
B. Gas tungsten arc welding (GTAW)
C. Gas metal arc welding (GMAW)
D. Oxyfuel welding
Rationale: GMAW uses a continuously supplied wire electrode that
serves as both the electrode and, depending on the application, the
filler metal. Shielding gas protects the molten weld pool from
atmospheric contamination.
2. What is the primary purpose of shielding gas during arc welding?
,A. Increase the hardness of the base metal
B. Prevent atmospheric gases from contaminating the weld pool
C. Cool the electrode
D. Increase the electrical resistance of the circuit
Rationale: Oxygen, nitrogen, and moisture from the atmosphere can
cause porosity, embrittlement, oxidation, and other weld defects.
Shielding gas displaces atmospheric gases around the arc and molten
metal.
3. In SMAW, what component provides the filler metal for the weld?
A. Tungsten electrode
B. Shielding-gas nozzle
C. Consumable coated electrode
D. Copper backing bar
Rationale: SMAW electrodes are consumable. Their metal core
supplies filler metal while the coating produces shielding gases and
slag that protect the weld as it solidifies.
4. What is the function of welding slag?
A. Increase the welding machine voltage
B. Protect the molten and cooling weld metal from atmospheric
contamination
,C. Prevent current from flowing through the electrode
D. Replace the need for a welding helmet
Rationale: Slag forms over the weld bead and shields the hot metal
from the atmosphere. It must generally be removed between passes
when required to prevent inclusions and other defects.
5. Which welding process normally uses a nonconsumable tungsten
electrode?
A. SMAW
B. GMAW
C. FCAW
D. GTAW
Rationale: GTAW, commonly called TIG welding, uses a
nonconsumable tungsten electrode to establish the arc. Filler metal
may be added separately when required.
6. What does FCAW stand for?
A. Flux-cored aluminum welding
B. Flux-cored arc welding
C. Forced-current arc welding
D. Fusion-controlled arc welding
, Rationale: FCAW is Flux-Cored Arc Welding. It uses a tubular electrode
containing flux. Depending on the electrode type, shielding may come
from the flux, an external shielding gas, or both.
7. What is the purpose of a welding procedure specification (WPS)?
A. Establish employee vacation schedules
B. Determine the contractor's insurance premium
C. Specify the qualified variables and requirements for producing a
weld
D. Replace all welding inspection requirements
Rationale: A WPS provides controlled welding parameters and
essential requirements such as process, materials, electrode or filler
metal, preheat, interpass temperature, and electrical settings as
applicable.
8. What is preheating primarily intended to accomplish when
welding steel?
A. Make the electrode nonconductive
B. Reduce the cooling rate and help minimize cracking
C. Eliminate the need for shielding
D. Increase atmospheric humidity
