Certified Fire Investigator Practice Exam

What is the primary function of a ground-fault circuit-interrupter (GFCI)?

1. To provide overcurrent protection

2. To detect ground faults

3. To control electrical circuits

4. To regulate voltage levels

The correct answer is: To detect ground faults

The primary function of a ground-fault circuit-interrupter (GFCI) is to detect ground faults. A ground fault occurs when electricity takes an unintended path to the ground, which can happen when there is a failure in insulation, a defective appliance, or if someone accidentally makes contact with a live part of a circuit. GFCIs are designed to monitor the current flowing through the circuit and can quickly disconnect power when they sense an imbalance between the incoming and outgoing current. This imbalance is indicative of a leakage of current, which can pose a serious shock hazard to individuals. By cutting off the electrical supply, GFCIs significantly enhance safety, particularly in areas with increased risk of electrical shock, such as bathrooms, kitchens, and outdoor environments. The other options, while related to electrical safety and function, do not pertain specifically to the critical role of a GFCI. Overcurrent protection, for instance, is achieved through circuit breakers or fuses that prevent excess current from causing overheating and fires. Controlling electrical circuits is a broader function that covers various devices, whereas regulating voltage levels is typically managed by other equipment such as voltage regulators, rather than GFCIs. Thus, the emphasis on detecting ground faults pinpoints the unique and