we know that when a glass rod is rubbed with a piece of silk, acquires the property of attracting light objects like bits of paper, straw, pith balls or even dust particles towards it .the glass rod is said to be electrified or charged. Similarly, a plastic comb gets electrified on passing through dry hair.
- The metallic bodies of cars and trucks also get charged because of friction between them and the air rushing past them. This charge being large can be dangerous in case of a petrol tanker. That’s why petrol tankers often have a metal chain dragging along the ground. The charged produced leaks through the ground this chain. Now a day, the tyres of cars and trucks made by adding a carbon compound to this rubber .this facilitates the charges built up on the body of the vehicles to leak to the ground.
The charges on insulating bodies cannot move on their own. That’s why they are called static charge. the branch of physics, which deals with deals with the study of charges at rest, the forces between the static charges, at rest, the forces between the static charges, fields and potentials due to these charges is called electrostatics or static electricity or even frictional electricity.
This phenomenon was discovered around 600bc by a Greek philosopher ‘Thales of Miletus’.
According to William Gilbert Charge is something possessed by material objects that make it possible for them to expert electrical force and to respond to electrical force.
- me = 9.10940 × 10-31 kg
- mp = 1.67262 × 10-27 kg
- mn = 1.67493 × 10-27 kg
An electron repels another electron at a distance of 1 cm with a force = 2.3 × 10-24 N. this force is called electric force.
The electrons must have some additional property [other than their mass], which is responsible for the electric force between them. This additional property of electrons, which gives rise to electric force between 2 electrons, is called electric charge. Just as masses are responsible for the gravitational force, charges are responsible for electric force. two protons placed at a distance of 1 cm also repel each other with the same force = 2.3 × 10-24 N. it show that protons also have charges which in magnitude, must be equal to charge on electron. Two neutrons placed at a distance of 1cm attract each other with a force = 1.9 × 10-60 N, which is the gravitational force due to their masses.
to be continued…………………….