SENSE Module #5 GMAW
1. In GMAW, the shielding for the molten metal is accomplished through the use of:
Answer: Inert and reactive gases.
Explanation: The shielding gas protects the molten weld pool from atmospheric contamination
(oxygen, nitrogen, hydrogen) which can cause weld defects. Common gases include argon (inert)
and mixtures with CO₂ (reactive).
2. GMAW is the abbreviation for:
Answer: Gas Metal Arc Welding.
Explanation: GMAW is a welding process where an electric arc forms between a consumable
wire electrode and the workpiece metal, with shielding provided by a gas.
3. In GMAW, insufficient gas flow can cause:
Answer: Porosity.
Explanation: Without adequate gas flow, air can contaminate the weld pool, leading to trapped
gas pockets (porosity) that weaken the weld.
4. A worn contact tube results in:
Answer: Poor arc starts.
Explanation: The contact tube delivers current to the electrode wire; wear can cause inconsistent
electrical contact, leading to unstable arc initiation.
5. The benefit of copper coated electrode wires is:
Answer: Better arc starts, increased contact tip life, and improved wire feeding.
Explanation: Copper coating improves electrical conductivity and reduces friction inside the
contact tube.
6. What type of power source is used for GMAW?
Answer: Constant Voltage.
, Explanation: GMAW machines use a constant voltage power supply to maintain a steady arc
length and stable welding conditions.
7. In GMAW, which type of metal transfer is restricted to flat position and horizontal fillet
welds?
Answer: Spray Transfer.
Explanation: Spray transfer produces a fine, high-energy arc with minimal spatter, best suited for
flat and horizontal welds due to its fluid weld pool.
8. What type of electrode wire is used with GMAW?
Answer: Solid.
Explanation: GMAW commonly uses solid wire electrodes, which provide a clean weld and are
compatible with various shielding gases.
9. In GMAW, the amperage is controlled by adjusting the:
Answer: Wire feed speed.
Explanation: Increasing the wire feed speed increases current (amperage), affecting penetration
and weld bead size.
10. In GMAW, electrode extension is defined as the distance from the:
Answer: End of the contact tube to the tip of the wire.
Explanation: Proper electrode extension ensures stable arc characteristics and consistent
welding.
11. Which AWS electrode classification is correct for GMAW wire?
Answer: ER70S-3.
Explanation: This classification indicates a solid wire with tensile strength of 70,000 psi and
certain chemical composition suited for carbon steel.
12. Which of the following is considered an advantage of the GMAW process?
Answer: Higher deposition rates than manual processes, easy to use compared to manual
processes, and less electrode waste than with SMAW.
Explanation: GMAW is efficient and suitable for high production with less operator skill
required compared to Shielded Metal Arc Welding (SMAW).
1. In GMAW, the shielding for the molten metal is accomplished through the use of:
Answer: Inert and reactive gases.
Explanation: The shielding gas protects the molten weld pool from atmospheric contamination
(oxygen, nitrogen, hydrogen) which can cause weld defects. Common gases include argon (inert)
and mixtures with CO₂ (reactive).
2. GMAW is the abbreviation for:
Answer: Gas Metal Arc Welding.
Explanation: GMAW is a welding process where an electric arc forms between a consumable
wire electrode and the workpiece metal, with shielding provided by a gas.
3. In GMAW, insufficient gas flow can cause:
Answer: Porosity.
Explanation: Without adequate gas flow, air can contaminate the weld pool, leading to trapped
gas pockets (porosity) that weaken the weld.
4. A worn contact tube results in:
Answer: Poor arc starts.
Explanation: The contact tube delivers current to the electrode wire; wear can cause inconsistent
electrical contact, leading to unstable arc initiation.
5. The benefit of copper coated electrode wires is:
Answer: Better arc starts, increased contact tip life, and improved wire feeding.
Explanation: Copper coating improves electrical conductivity and reduces friction inside the
contact tube.
6. What type of power source is used for GMAW?
Answer: Constant Voltage.
, Explanation: GMAW machines use a constant voltage power supply to maintain a steady arc
length and stable welding conditions.
7. In GMAW, which type of metal transfer is restricted to flat position and horizontal fillet
welds?
Answer: Spray Transfer.
Explanation: Spray transfer produces a fine, high-energy arc with minimal spatter, best suited for
flat and horizontal welds due to its fluid weld pool.
8. What type of electrode wire is used with GMAW?
Answer: Solid.
Explanation: GMAW commonly uses solid wire electrodes, which provide a clean weld and are
compatible with various shielding gases.
9. In GMAW, the amperage is controlled by adjusting the:
Answer: Wire feed speed.
Explanation: Increasing the wire feed speed increases current (amperage), affecting penetration
and weld bead size.
10. In GMAW, electrode extension is defined as the distance from the:
Answer: End of the contact tube to the tip of the wire.
Explanation: Proper electrode extension ensures stable arc characteristics and consistent
welding.
11. Which AWS electrode classification is correct for GMAW wire?
Answer: ER70S-3.
Explanation: This classification indicates a solid wire with tensile strength of 70,000 psi and
certain chemical composition suited for carbon steel.
12. Which of the following is considered an advantage of the GMAW process?
Answer: Higher deposition rates than manual processes, easy to use compared to manual
processes, and less electrode waste than with SMAW.
Explanation: GMAW is efficient and suitable for high production with less operator skill
required compared to Shielded Metal Arc Welding (SMAW).
