Which device is often used to control excessive current flow in a circuit?

The circuit breaker is a crucial device in electrical systems designed to protect circuits from excessive current flow, which can lead to overheating and potential damage or fire. When the current exceeds a predetermined level, the circuit breaker automatically interrupts the flow of electricity, effectively opening the circuit and preventing further risk of overcurrent situations. This function is critical for maintaining safety and integrity in electrical installations and is widely used in residential, commercial, and industrial applications.

While capacitors, resistors, and inductors are important components in managing various electrical characteristics, they do not primarily serve the purpose of controlling excessive current flow. Capacitors can store and release energy but are not designed to interrupt current during overcurrent conditions. Resistors limit current flow when installed in a circuit, yet they cannot shut down the circuit like a circuit breaker can. Inductors store energy in a magnetic field and can influence the flow of current, but they do not provide a protective mechanism against overcurrent. Thus, the circuit breaker stands out as the correct choice for controlling excessive current flow.