The domestic supply socket consists of three terminals namely live, neutral and earth. The Potential Difference (PD) between live and neutral is almost of constant magnitude while the PD between neutral and earth should be ideally zero. But practically it is not zero. A small PD exists between the neutral and earth terminal due to the voltage drop across the resistance of the neutral wire. Its value ranges from 1-6V depends on the loads connected and the amount of unbalance between the phases. The voltage is maximum at peak hours at midday. It is small in the morning and evening. Till now...