1. State board of electricity provides us the electric power supply for the houses and factories.
2. This is supplied through underground cables or overhead wires on poles. These wires or cables are of three types : phase wire (or live wire), neutral wire and earth wire.
3. These wires coming from power sub stations are connected to an electric meter installed in a house or a factory. The potential difference between the live wire and neutral wire is 220V-250V.
4. The output power from electric meter is taken to the main switch. A fuse known as main fuse is placed in the path of live or phase wire.
5. The output electric power from the main switch is distributed to the domestic electric circuit.
6. In each separate circuit, different appliances can be connected across the live and neutral wires. Each appliance has equal potential difference, they are connected parallel to each other.