In an electrical circuit, what is the purpose of the ground wire?

The purpose of the ground wire in an electrical circuit is primarily to protect against electrical shock. Grounding provides a safe pathway for electricity to flow back to the ground in case of a fault, such as a short circuit or insulation failure. This helps to prevent the buildup of dangerous voltages that could result in electrical shock if a person touches a conductive part of the circuit.

Grounding systems are essential for safety in electrical installations because they help to ensure that in the event of a fault, excess current is directed away from people and sensitive equipment. For example, when a fault occurs, the ground wire allows the circuit to trip, thereby disconnecting the power supply and reducing the risk of injury or equipment damage.

The other choices relate to different functions that can occur in electrical systems. Carrying current is typically the function of live wires, while reducing resistance is related more to the materials and design of the circuit itself. Increasing current capacity pertains to the gauge of the wires used or the design of the circuit, rather than the function of the ground wire. Therefore, the most accurate description of the role of the ground wire is its contribution to safety by protecting against electrical shock.