What is the function of a GFCI outlet?

• A. Provides overcurrent protection by interrupting excessive current.
• B. Maintains a constant voltage to outlets.
• C. Detects differences between live and neutral currents and trips to prevent shock.
• D. Acts as a power factor correction device.

Answer: (C)

A GFCI’s job is to protect you from grounding faults by sensing any difference between the current in the hot and the neutral. Under normal use those currents match. If current leaks to ground—such as through a person touching a live surface in a wet area—the currents no longer balance. The GFCI detects this imbalance and trips, cutting power in a fraction of a second to prevent electric shock. This is distinct from devices that provide overcurrent protection (like a circuit breaker), those that regulate voltage, or those that improve efficiency by correcting power factor.