What is the purpose of a circuit breaker?

The purpose of a circuit breaker is to protect electrical circuits from overloads and short circuits. Circuit breakers serve a critical safety function in electrical systems by automatically interrupting the flow of electricity when they detect an anomaly such as excessive current. This prevents overheating of wires, potential fire hazards, and damage to electrical devices and components.

In the event of a short circuit, where current flows along an unintended path, or an overload occurs when electrical demand exceeds the circuit's capacity, the circuit breaker quickly trips to cut off the electrical supply. This automatic response is vital to maintaining safety and functionality within an electrical system, ensuring that both equipment and personnel are protected from electrical hazards.

The other choices relate to different functions that are not the primary purpose of a circuit breaker. Converting AC to DC electricity and regulating electrical voltage pertain to different devices such as rectifiers and voltage regulators. Measuring electrical resistance is typically performed by multimeters or ohmmeters, not circuit breakers.