When current in an electric circuit abruptly rises due to some default in the circuit, it is called short – circuiting. Two precautions to Prevent it are:
(i) Wires should be well insulated.
(ii) Too many appliances should not be connected to a single socket.
The colour of insulation of earth wire green. The metallic appliances are earthed so that the earth wire provides a low resistance conducting path for the current. Thus it ensures that any leakage of current to the metallic body of the appliance keeps its potential to that of the earth and the user may not get severe electric shock.