Question

what is the function of an earth wire in a domestic electric circuit?

Answer 1

To avoid the risk of electric shocks , the metal body of an electrical appliances is earthed.
Earthing means to connect the metal case of electrical appliances to earth at zero potential by means of earth wire.

In house hold circuits , we have three wires, the live wire, the neutral wire and earth wire.
One end of earth wire is buried in earth.
we connect the earth wire to metal casing of electrical appliances by using three pin plug.
If by chance, live wire touches any metal case parts of appliances then current passes directly to earth.
hence earthing is used as safety measure to prevent shock from metal objects.

Answer 2

Answer:

Whenever livewire accidently touches the body of the metallic electric appliances the earth wire. since the current to the earth the earth wire serves as a protective conductor which saves as from electric shocks