Which device automatically stops electricity flow when an overload is detected?

A circuit breaker is designed to automatically stop the flow of electricity when it detects an overload, thus protecting the electrical circuit from damage. It functions by sensing current levels within the system. When the current exceeds a predetermined threshold, indicating an overload condition, the circuit breaker trips, interrupting the circuit and disconnecting the electrical supply. This prevents overheating and potential fire hazards that could result from excessive current flow.

Unlike a fuse, which also protects against overloads but does so by melting its internal element and requiring replacement after it blows, a circuit breaker can be reset and reused once the fault has been cleared. Capacitors and transformers serve different purposes in electrical systems; capacitors store electrical energy for various applications such as power factor correction, and transformers are used to step up or step down voltage levels in alternating current (AC) systems. Neither of these devices automatically interrupts circuits in response to overload conditions.