What device prevents excessive current from passing through a circuit?

A circuit breaker is designed to prevent excessive current from passing through a circuit by automatically interrupting the flow of electricity when it detects an overload or short circuit. This function is crucial for maintaining safety within electrical systems, as it helps prevent overheating, potential fires, and equipment damage.

When the current exceeds a certain threshold, the circuit breaker trips, effectively opening the circuit and stopping the electrical flow until it can be reset. This mechanism ensures that the circuit remains protected and operational, providing a reliable way to manage electrical safety.

While a fuse also serves a similar purpose, it operates by melting a wire inside it when the current is too high, which permanently breaks the circuit until the fuse is replaced. On the other hand, a transformer is used to change the voltage of alternating current, and a conductor is simply a material that allows electricity to flow.