Question

1. what is the recommended method for cleaning the base metal before gmaw welding?

a) sanding with fine - grit paper
b) using a wire brush or grinder
c) wiping with a damp cloth
d) applying a layer of paint

1. which type of gmaw uses a continuously fed, consumable electrode wire that contains a flux core?

a) gmaw - p
b) gmaw - a
c) fcaw
d) saw

1. what does the term duty cycle refer to in gmaw equipment?

a) the time it takes to complete a weld
b) the maximum current output of the welding machine
c) the ratio of welding time to cooling time
d) the type of shielding gas used

1. when welding thicker materials with gmaw, which welding technique is often used to ensure proper penetration?

a) weaving
b) stitching
c) stringer bead
d) circumferential bead

1. what is the purpose of the ground clamp in gmaw welding?

a) hold the work piece in place
b) provide electrical contact to complete the circuit
c) control the shielding gas flow
d) feed the welding wire

1. which of the following is not a common gmaw process variation?

a) short circuit transfer
b) spray transfer
c) pulsed transfer
d) tig transfer

Explanation:

• Question 25: Before GMAW welding, using a wire brush or grinder is the standard method to clean base metal as it effectively removes contaminants like rust, scale, etc. Sanding with fine - grit paper may not be as effective for heavy contaminants, wiping with a damp cloth is insufficient for metal surface cleaning, and applying paint is not a cleaning method.
• Question 26: FCAW (Flux - Cored Arc Welding) uses a continuously fed, consumable electrode wire that contains a flux core. GMAW - P (Pulsed Gas Metal Arc Welding) and GMAW - A (not a standard major type in common GMAW categorizations in this context) do not have the flux - cored wire characteristic. SAW (Submerged Arc Welding) has a different electrode and process setup.
• Question 27: The duty cycle in GMAW equipment refers to the ratio of welding time to cooling time. It is not about the time to complete a weld (that's cycle time in a different sense), not the maximum current output (which is a separate parameter), and not related to shielding gas type.
• Question 28: When welding thicker materials with GMAW, weaving is often used. It moves the electrode back and forth, allowing for wider heat distribution and better penetration. Stitching is more for tacking or intermittent welding, stringer bead is a single pass bead without the side - to - side movement for wider coverage, and circumferential bead is related to circular welding paths, not specifically for thick - material penetration.
• Question 29: The ground clamp in GMAW welding provides electrical contact to complete the circuit. It is not for holding the work - piece (clamps or fixtures are for that), not for controlling shielding gas flow (a separate regulator does that), and not for feeding the welding wire (the wire feeder mechanism does that).
• Question 30: TIG transfer is not a common GMAW process variation. GMAW has short - circuit transfer, spray transfer, and pulsed transfer as its main process variations. TIG (Tungsten Inert Gas) is a different welding process with its own transfer mechanisms.

Answer:

1. b) Using a wire brush or grinder
2. c) FCAW
3. c) The ratio of welding time to cooling time
4. a) Weaving
5. b) Provide electrical contact to complete the circuit
6. d) TIG transfer