What is the function of a ground fault circuit interrupter (GFCI)?

The function of a ground fault circuit interrupter (GFCI) is to detect an imbalance in current and prevent shock. GFCIs are designed to protect people from electric shock by monitoring the amount of electricity flowing through a circuit. They continuously check the incoming and outgoing current; if they sense any difference—indicating that current is leaking through an unintended path, such as a person's body—they quickly disconnect the circuit, typically in a fraction of a second. This rapid response helps to prevent severe injuries or fatalities that could result from electrical shocks.

This mechanism is particularly important in areas where water is present, such as bathrooms and kitchens, where the risk of shock is higher. The other options do not pertain to the function of a GFCI; for instance, increasing voltage, regulating voltage levels, or monitoring temperature are tasks handled by different electrical devices or systems that serve distinct purposes.