What does a circuit breaker do in an electrical system?

A circuit breaker is a crucial component in an electrical system designed specifically to protect the wiring and devices connected within that system from the potentially damaging effects of overcurrent conditions. When the electrical current flowing through the circuit exceeds a predetermined level due to a fault, such as a short circuit or an overload, the circuit breaker interrupts the flow of electricity by opening the circuit. This action helps prevent overheating, fires, and damage to electrical components, ensuring the safety and reliability of the electrical system.

The other choices, while they refer to important functions in electrical systems, do not accurately describe the specific role of a circuit breaker. For instance, storing electrical energy pertains more to devices like capacitors or batteries, regulating voltage levels involves equipment such as transformers or voltage regulators, and facilitating power transfer is generally associated with switches or power distribution elements in the system. Thus, the main function of a circuit breaker is to prevent overcurrent conditions, reinforcing its role as a protective device in electrical installations.