In electrical systems, what is the main role of a circuit breaker?

The main role of a circuit breaker is to protect against overcurrent. Circuit breakers are designed to automatically interrupt the flow of electricity in a circuit when they detect an overcurrent condition. This overcurrent can occur due to various reasons, such as short circuits, equipment malfunctions, or excessive load on the circuit.

By tripping and disconnecting the circuit, the circuit breaker prevents potential hazards such as overheating, electrical fires, and damage to wiring or appliances. This protective function is crucial for maintaining safety in electrical systems, ensuring that the circuit can be restored once the underlying issue is resolved.

The other options, such as enhancing efficiency, providing control, or connecting circuits, relate to different aspects of electrical systems but do not capture the primary protective function of a circuit breaker. While circuit breakers may indirectly assist with control or can be part of an efficient system, their fundamental purpose is to safeguard against overcurrent situations.