What is the function of a circuit breaker?

The function of a circuit breaker is to interrupt the flow of electricity in case of a fault. Circuit breakers are safety devices designed to protect electrical circuits from damage caused by overloads or short circuits. When the circuit experiences a fault, such as too much current flowing through it, the circuit breaker automatically trips and breaks the electrical circuit. This action prevents potential hazards like electrical fires or damage to equipment that may occur if the fault is allowed to continue. By breaking the circuit, it ensures the safety of both the electrical system and the users relying on that system.

The other options do not accurately describe the function of a circuit breaker. Increasing electrical current, providing backup power supply, and dimming the brightness of lights pertain to different types of electrical devices and systems.