What does a ground fault circuit interrupter (GFCI) do?

A ground fault circuit interrupter (GFCI) is designed specifically to enhance electrical safety by detecting ground faults and interrupting the circuit when such a fault is present. A ground fault occurs when electricity flows through an unintended path to the ground, which can happen when there is a malfunction in the wiring or when someone accidentally comes into contact with live electrical components.

The GFCI monitors the current flowing through the circuit and compares the input current (the current traveling to the outlet) with the output current (the current returning from the outlet). If it detects any imbalance between these two currents—indicating that some of the current is leaking to the ground—the GFCI will quickly shut off the power to prevent electric shock or electrical fires.

This critical protective function makes the GFCI an essential safety device, particularly in areas where electrical devices are used near water, such as kitchens and bathrooms. The other options, while relevant to electrical systems, do not describe the specific functionality of a GFCI. For instance, preventing voltage surges, increasing conductivity, or providing additional current are not roles played by a GFCI device.