What does a GFCI do when it detects a fault?

A Ground Fault Circuit Interrupter (GFCI) is designed to protect people from electric shock by monitoring the flow of electricity through a circuit. When it detects an imbalance in the electrical current, which typically indicates a fault such as a short circuit or current leaking to ground, the GFCI acts swiftly to shut off power. This disconnection occurs in less than 1/40 of a second, minimizing the risk of serious injury or electrocution. The rapid response of the GFCI is crucial in preventing accidents, especially in wet or outdoor environments where the risk of electric shock is increased.

The other options describe actions that are not within the function of a GFCI. It does not increase voltage or strengthen the electrical circuit, nor does it provide an alternative power supply. The primary purpose of a GFCI is to ensure safety by quickly interrupting the electrical flow in the event of a fault.