Charging a Body by Conduction

Description:

We know that a body applies force only if there is net charge over it. According to electron theory the net charge is created over a body either by increasing or decreasing the number of electrons in it.

These are two methods for creating charge on a body.

• Method of conduction.
• Method of induction.

Method of Conduction

If we take a body having positive and negative charged particles in equal number, so that net charge on the body remains zero. Now, if an excess negatively charged body (say plastic) is brought in contact with the neutral body the transfer of electrons takes place from excess charged body to a neutral body. This process is called conduction.

This transfer of electrons takes place because of strong repulsion between the similar charges and after coming in contact with the conductor electrons get a path to move.

These electrons flow until there is equal force at both the sides of conductor. When the electrons stops flowing the plastic is removed and then the net charge in the neutral body does not remains zero. The net charge becomes (-ne).

Note −

1. Transfer of electron takes place because of strong force of repulsion between the similar charges in the giving body.

2. In a conductor the excess charges are always located at the surface. This is because similar charges repel each other. But they donot move out in the air because air is an insulator.

3. Two things that are mandatory for charging a body by conduction process −

• A charged body
• Contact between the neutral and charged body