What is the primary function of a circuit breaker?

The primary function of a circuit breaker is to protect electrical circuits from overload and short circuits. A circuit breaker acts as an automatic switch that interrupts the flow of electrical current when it detects excessive current that could lead to damage or hazards, such as overheating or fire. By interrupting the circuit, the breaker prevents further damage to the electrical system and maintains safety.

In addition to its protective capabilities, a circuit breaker enables easy resetting after the fault condition has been cleared, allowing the circuit to be restored to normal operation without the need for replacing fuses or other components, which enhances convenience and safety for users.

The other options, while related to electrical systems, do not define the primary purpose of a circuit breaker. Providing a path for current flow and stepping down voltage levels pertain to conductors and transformers, respectively. Converting AC to DC involves rectification, which is unrelated to the operation of a circuit breaker. Therefore, the emphasis on protection against overload and short circuits clearly establishes why this answer is the most accurate in describing the role of a circuit breaker.