What is the function of a circuit breaker in an electrical circuit?

• A. A device that interrupts or breaks the flow of electricity in a circuit
• B. A fuse that melts when overloaded
• C. A switch that only turns off power
• D. A battery backup device

Answer: (A)

A circuit breaker is a safety device that automatically stops the flow of electricity when something goes wrong in a circuit, usually when the current becomes too high due to overload or a short circuit. It detects the excess current and trips a switch to open the circuit, protecting wires, outlets, and devices from overheating and reducing fire risk. Unlike a fuse, which melts and must be replaced after it blows, a circuit breaker can be reset once the fault is fixed. It’s different from a regular switch, which only turns power on or off and doesn’t automatically respond to abnormal current. And it’s not a power source like a battery backup; its job is protection, not supplying energy.