What is the purpose of a ground wire in an electrical system?

The purpose of a ground wire in an electrical system is to provide a safe pathway for fault currents. In the event of a short circuit or another fault condition, the ground wire directs the excess electrical current safely into the ground. This helps prevent electrical shocks, protects equipment from damage, and reduces the risk of fire that could result from faulty wiring or malfunctioning devices.

Ground wires are critical for ensuring safety by establishing a reference point in the electrical system, which helps to maintain proper voltage levels. When faults occur, the ground wire effectively allows the electrical current to bypass the intended path and provides a means for the electrical current to return safely to the earth, thereby tripping circuit breakers or blowing fuses, which turn off the electrical supply.

This function is distinct from the roles that may be implied by the other options, which address connectivity, voltage increase, or current decrease but do not directly relate to the safety mechanism established by the ground wire.