Question

use of earth wire plz explain​

Answer 1

earth wire Earthing is used to protect you from an electric shock. It does this by providing a path (a protective conductor) for a fault current to flow to earth. It also causes the protective device (either a circuit-breaker or fuse) to switch off the electric current to the circuit that has the fault

Answer 2

Earth wire is used to prevent us from electric shock. It is because some times,(During lightning) The current through a wire will increase and the required current amount will increase .

Due to that the electric device ( as over current supplied to it) may get blasted.

To prevent this earth wire is used , which will send unwanted electric current to ground and ground will absorb

Have you seen the third big pin in a switch..? have u observed why it is there ..? In some cases like electric iron why we can see it has 3 pins ? It is because electric iron consumes lot of current

Some times this current will start leaking from the switch and if a person accidentally touch that switch he will suffer from electric shock

That is why we use earth wire