Which device is used to provide overcurrent protection in a circuit?

The device used to provide overcurrent protection in a circuit is a fuse. A fuse is designed to protect electrical circuits by melting and breaking the circuit if the current exceeds a predetermined level. This process effectively disconnects the circuit to prevent damage to wiring or connected devices that could result from excessive current flow.

In contrast, a capacitor serves to store electrical energy temporarily and is not designed for overcurrent protection. A transformer is used to change voltage levels in a circuit and does not provide overcurrent protection either. A relay is employed to control the flow of electricity in a circuit but does not function as an overcurrent protective device. This distinction highlights the specific role of a fuse in ensuring safety by preventing potential damage from overcurrent conditions.