What is the primary purpose of circuit breakers?

The primary purpose of circuit breakers is to interrupt the flow of electricity during overload or short circuits. Circuit breakers are crucial safety devices in electrical systems. They are designed to protect circuits from excessive current that can lead to overheating, potential fires, or damage to electrical devices. When the current exceeds a predetermined threshold due to an overload or a short circuit condition, the circuit breaker automatically trips, effectively interrupting the electrical flow. This action prevents further damage to the electrical system and enhances safety for both equipment and personnel.

In contrast, regulating voltage levels pertains to devices such as voltage regulators or transformers, which do not serve the same protective function as circuit breakers. Enhancing electrical efficiency is typically related to optimizing how electricity is used or improving energy conversion processes, rather than protecting against electrical faults. Converting AC to DC power is the role of rectifiers; this function is unrelated to the protective measures that circuit breakers provide. Thus, the correct option encapsulates the essential protective role that circuit breakers play in electrical systems.