What is the primary purpose of a GFCI?

• A. Trips on ground fault; quickly cut off current.
• B. Regulates voltage.
• C. Increases current capacity.
• D. Changes breaker color.

Answer: (A)

Ground fault protection is the key idea. A GFCI watches the current on the hot and the return path and looks for any imbalance. If some current leaks to ground—like through a person who touches a live surface—the device senses the difference and immediately opens the circuit, cutting off power to prevent an electric shock. This is especially important in wet or outdoor locations, where the risk of ground fault is higher. A GFCI doesn’t regulate voltage, doesn’t increase current capacity, and doesn’t change the breaker’s color.