What is the primary purpose of a Ground Fault Circuit Interrupter (GFCI)?

• A. To store electrical energy.
• B. To protect against electrical shock by opening the circuit when grounding occurs.
• C. To regulate voltage in a circuit.
• D. To convert AC to DC.

Answer: (B)

Protecting people from electric shock is the primary purpose. A GFCI continuously compares the current flowing through the hot and neutral conductors. If any current leaks outside the intended path—typically through a person to ground—the device senses the difference and quickly opens the circuit to cut power. This rapid interruption greatly reduces the risk of serious injury, especially in wet or damp areas where ground faults are more likely. It’s not designed to store energy, regulate voltage, or convert AC to DC, which are functions of other electrical devices.