Fuse

It is a safety device made of a soft metal with low melting point which melts to break an electrical circuit when excess current flows through. It is inserted in electrical circuits to protect the circuit.

Every electrical appliance has a maximum amount of current it can tolerate, therefore if current flowing through it exceeds its threshold, the appliance would become over heated and eventually damaged.

Fuses are placed in live wires so that when the fuse breaks open, the live wire is disconnected.