Question

What do you mean by the term local earthing? Explain how it is done.

Answer 1

Hint: Earthing is the process in which we transfer the charge directly to the earth plate, by using low resistance electrical cables or wires from the appliance. This ensures the potential of the appliance where this wire is connected i.e. the outer body becomes zero. The earthing is done for the safety of peoples.

Complete step-by-step solution:
Local earthing means the connection of copper wire to a copper plate which is placed deep inside the ground.This arrangement is done near the main line i.e. near the kWh meter in a house. So that whenever a high voltage situation occurs the earthed copper wire would send the current to the ground. This is the way in which local earthing is done. The same process is applied to the local home appliances to get rid of the high voltage situation by mistake of the person.
Actually what happens is, when we bring a charged body either positively charged or negatively charged in contact with the earth, all the excess charge on the body flows to the earth by causing a momentary current to pass to the ground through the connecting conductor . This process of the charge transfer to the earth is called grounding or earthing.

Note: All the appliances or near the Kwh meter during earthing we should use copper wire since it allows charges to flow faster than other wiring materials. As copper is a very good conductor of electricity. If we use high resistive wire such as nichrome wire it may lead to an un conventional flow of charge or current.