Which device is used to detect ground faults in electrical circuits?

The Ground Fault Circuit Interrupter (GFCI) is specifically designed to detect ground faults in electrical circuits. A ground fault occurs when electricity flows through an unintended path, which can happen when there is a fault in the insulation of wires or when electrical equipment comes into contact with water. The GFCI continuously monitors the current flowing through the circuit. If it detects a difference in the current between the hot and neutral wires, it recognizes this as a potential ground fault condition and quickly disconnects the power to prevent electric shock or fire hazards.

In contrast, a fuse functions as a protective device that breaks the circuit if the current exceeds a certain level, but it does not specifically detect ground faults. Circuit breakers also serve to protect circuits from overload and short circuits but lack the specialized ground fault detection capabilities of a GFCI. A transformer is primarily used to transfer electrical energy between circuits through electromagnetic induction and does not detect faults. Thus, the GFCI stands out as the only device designed to specifically address ground faults, making it the correct choice in this context.