Fuses break the electric circuit when the current becomes very strong owing to any overload. As a result, the wires are never too hot, and a fire is prevented. In safety fuses, such as those used in cars or in screw-locking devices in homes, a thin wire inside the fuse melts when it gets heated by a very strong electric current. The fuse blows and must be replaced. In modern fuses, the circuit is broken with the help of an electromagnet, which ‘jumps out’ to break the circuit. When the fault has been fixed it is easily reset by pressing the switch.
