What is the function of a circuit breaker?

A circuit breaker is a crucial safety device in electrical systems, designed primarily to automatically interrupt power flow when it detects an overload or a fault condition. This function is essential because it helps prevent damage to electrical circuits and equipment, minimizes the risk of fire hazards, and ensures that the circuit can be safely reset after the fault is addressed. By automatically breaking the circuit, these devices protect both the wiring and any connected devices from excessive current that could lead to overheating or failure.

The other choices do not align with the primary role of a circuit breaker. Stabilizing voltage levels involves other equipment like voltage regulators or transformers. Converting AC to DC is the function of rectifiers or power supplies, not circuit breakers. Measuring electrical resistance pertains to ohmmeters or multimeters, which are used for diagnostics and testing, rather than for circuit protection or interruption. Thus, the role of a circuit breaker as an automatic interruption mechanism is fundamental for safety and effective power management in electrical systems.