Question

Explain how the fuse melts when a short cir- cuited appliance gets earthed?

Answer 1

Dear Student,
​At the time of short circuit the ground and the neutral comes in direct contact now as because current passes without load connected, a large amount of current passes through the fuse which is connected in series with the household wiring. Now each fuse has its limit of carrying current; if current through it flows beyond the limit heat develops in the wire according to the relation H = I²Rt . Since the fuse wire is of low melting point it melts breaks the circuit.

Regards