What is the role of a circuit breaker in electrical systems?

A circuit breaker plays a crucial role in electrical systems primarily by preventing overload. It is designed to automatically interrupt the flow of electricity in a circuit when it detects an excessive current that could potentially cause damage or pose safety hazards, such as overheating or fire. By breaking the circuit, the circuit breaker protects electrical devices and wiring from the adverse effects of overloads and short circuits.

In addition to its protective function, a circuit breaker can also facilitate safe maintenance and adjustments to electrical systems without the need for disconnecting power manually. This makes it an integral component in ensuring both the functionality and safety of electrical installations. The other options do not reflect the primary purpose of a circuit breaker in an electrical system.