What feature distinguishes a GFCI outlet from a standard outlet?

• A. It trips to interrupt power when a ground fault is detected.
• B. It increases voltage automatically.
• C. It provides emergency lighting.
• D. It reduces current to zero.

Answer: (B)

GFCI outlets are built to protect people by sensing ground faults and shutting off power when one is detected. They monitor the current in the hot and neutral paths; under normal use the currents match. If some current leaks to ground—such as through a person touching a live part—the imbalance triggers the device to rapidly cut power to the outlet. That preventive trip is the key feature that distinguishes a GFCI from a standard outlet.

The other options don’t describe this function. A GFCI does not automatically increase voltage, it does not provide emergency lighting, and it does not continuously reduce current to zero. It only trips to interrupt power when a ground fault condition is detected.