When the operator squeezes the trigger on a GMAW welding gun __________.

The correct answer indicates that when the operator squeezes the trigger on a GMAW (Gas Metal Arc Welding) welding gun, electricity, shielding gas, and wire meet at the contact tip. This is essential for the GMAW process because it describes how the system operates: the welding gun is designed to simultaneously deliver a continuous feed of filler metal (the wire), while also providing an electrical arc that melts both the wire and the base metal, along with shielding gas, which protects the weld pool from atmospheric contamination.

In GMAW, the contact tip is where the electrical arc is initiated and maintained. The wire is fed through the contact tip, and as the arc forms between the tip and the workpiece, it generates the heat necessary for welding. The shielding gas, which flows through the nozzle surrounding the contact tip, creates a protective envelope around the weld area, ensuring that no oxidants interfere with the weld.

This understanding of the GMAW process highlights the importance of the contact tip as a critical point where these elements converge to produce a successful weld.