Mention the desirable properties of fuse materials.
A fuse material must possess the properties as follows:
Low resistivity - It means, thin wires can be used that will offer less metal vapour after melting of the wire. Less metal vapour in the arc provides lower conductivity and therefore makes quenching of arc easier.
Low conductivity of the metal vapours itself.
Low melting point- It means that the temperature of the fuse material for normal currents stays on a low value. In earlier lead was used as fuse material because of its low melting point although thick wires of lead are required because of higher resistivity. For rewireable fuses alloys of lead and tin or tinned copper wires are generally used. In caridge fuses silver and silver alloys are utilized of lower ratings. Copper alloys are utilized in fuses of higher ratings.