Domestic circuit are the electric circuit wring done in the houses and buildings.
Electricity is transferred to our homes through a pair of insulated copper or aluminium wires. This pair consists of a red colour wire (called live wire, L), and a black colour wire (called neutral wire, N). In addition to these wires, a green colour wire known as the Earth wire, E is also connected with the circuit. In India, 220 V potential is supplied through live wire, while neutral wire has ground potential of zero volts.
In the above diagram, the pair of wires L and N first enter the main box, which is placed outside the house. From here, live wire L goes into the main fuse F1 having a high rating of about 50 A. Then, both wires enter the electricity meter that records the electricity consumed in units, where 1 unit = 1 kWh = 3.6 × 106 J. The wires then go to the main switch, S. Electricity supplied to the house can be cut off using this switch.
Domestic wiring in a house requires a number of electric devices to run simultaneously. Thus, they should be independent of each other i.e. the working of one device should not depend on the working of another device.
For example, the working of a fan should not be affected when a bulb in the room gets fused. In parallel circuits, if one appliance stops working, all other appliances work as usual. Hence, parallel circuiting is used in house wiring or in lights used to decorate buildings on occasions. This is done to ensure that if one bulb fuses, the others remain functioning.
