Which device plays a key role in protecting electrical circuits?

A circuit breaker is a crucial component in protecting electrical circuits because it serves as a safety device that automatically interrupts the flow of electricity when it detects an overload or a short circuit. This interruption helps prevent damage to the electrical system, reduces the risk of fire, and protects sensitive equipment from potentially damaging currents.

When a fault occurs, such as a short circuit, the circuit breaker quickly detects the abnormal current flow and opens the circuit, cutting off the electricity supply. This rapid response minimizes the chances of injury or property damage.

In contrast, while transformers, resistors, and capacitors are essential components in electrical systems, they do not serve the primary function of circuit protection. Transformers are used to change voltage levels, resistors regulate current flow, and capacitors store electrical energy, but none of these devices provide the protective functions that a circuit breaker does. Thus, the circuit breaker is integral to maintaining safe and reliable electrical operations.