What is the purpose of the ground clamp in a MIG welding setup?

• A. To protect the operator from sparks and flames.
• B. To hold the workpiece in place during welding.
• C. To complete the electrical circuit and provide a return path for welding current.
• D. To shield the arc from wind.

Answer: (C)

The ground clamp’s job is to complete the electrical circuit and provide the return path for welding current. In MIG welding, the power source sends current through the welding wire and across the arc into the workpiece; that current must return to the power supply. Attaching the ground clamp to the workpiece (or a clean, well-connected metal surface) gives a low-resistance path back, which stabilizes the arc and ensures proper heat and penetration. If the ground connection is poor, the arc can become unstable or wander, and weld quality suffers. The other options miss the electrical return role: protecting the operator refers to PPE, a separate hold-down device would be used for securing the piece, and shielding from wind is handled by shielding gas and proper setup, not the ground clamp.