What type of circuit protects against excess current and reduces shock hazards?

A Ground Fault Circuit Interrupter (GFCI) is specifically designed to protect against excess current and reduce the risk of electrical shock. It accomplishes this by constantly monitoring the current flowing through the circuit. If it detects any imbalance, such as when current is leaking due to a fault (for example, if a person touches a live wire), it quickly shuts off the power, effectively reducing the risk of shock or electrocution.

This makes GFCIs particularly vital in areas where moisture is present, such as bathrooms, kitchens, and outdoor settings, as they provide an added layer of safety compared to standard circuit breakers. In contrast, the other options, while related to electrical circuits, do not provide direct protection against shock hazards or the specific purpose of interrupting excess current due to ground faults. For instance, open circuits and short circuits refer to conditions within electrical wiring rather than protective devices, and transformers serve to change voltage levels rather than directly mitigate shock risks.