Question

Why does a Fuse wire should have higher resistance than the other wires in the circuit but it should not have high melting point. Why?

Answer 1

A normal fuse generally melts when the current passing through it is more than the safe amount. Thus, when the current increases, the heating effect also increases, and then the fuse wire melts. In this way, the circuit is saved.

If the fuse has a high resistance, then the amount of heat it generates also increases (as H=I^Rt). If it has a high melting point, the excess current will pass the fuse and affect the circuit. Thus, it should always be made of a material that is easy to melt, i.e it should have a low melting point.