Question

how does a fuse help in a domestic circuit?

Answer 1

The fuse breaks the circuit if a fault in an appliance causes too much current flow. This protects the wiring and the appliance if something goes wrong. The fuse contains a piece of wire that melts easily. If the current going through the fuse is too great, the wire heats up until it melts and breaks thecircuit.

Answer 2

Generally the whole house is protected by a circuit panel that uses circuit breakers instead of fuses. We no longer use fuses as a our main method. However, some devices have a built-in fuse protection of that item in and of itself rather than relying on the protection of the circuit breaker. For example, if you have an electrical drill, it might have a fuse, or if you ever used a sewer snake machine, it usually has some kind of overload protection circuit. The fuse is always on the "black wire" or the "hot side". It's never on the "white wire" or the "green wire".