PSI Barbering Practice Exam

In modern electric circuits, which of the following has replaced fuses and can be reset?

1. Relay

2. Fuse

3. Circuit breakers

4. Thermostat

The correct answer is: Circuit breakers

Circuit breakers have become a modern solution to the limitations of traditional fuses. They are designed to automatically interrupt the flow of electricity in the event of an overload or short circuit, thus protecting the circuit and connected devices from potential damage. One key advantage of circuit breakers over fuses is their ability to be reset after they trip. This eliminates the need for replacement, which is necessary with fuses once they have opened the circuit. The reset feature saves time and costs associated with purchasing new fuses. In contrast, while relays and thermostats play important roles in controlling electrical circuits, they do not serve the same function as circuit breakers. A relay is primarily used for switching circuits on and off, while a thermostat regulates temperature. Fuses, although they serve to protect circuits, do not have the capability to be reset and must be replaced when they blow. Thus, the modern utility and efficiency of circuit breakers in electrical systems highlight why they are preferred for protecting circuits and facilitating ease of maintenance.