Origin of Electric Charge in Electrostatics

Every atom is electrically neutral, containing as many as electrons as the number of proton in nucleus. Thus a body is charged if it has a charge imbalance or some net charge.

Electrons are transferred from the material whose work function is lower to the material whose work function is higher.

Charging by rubbing is due to actual transfer of electrons.

A positively charged body has lost some electrons and hence its mass reduces slightly. On the other hand, a negatively charged body has gained some electron and hence it’s mass increased slightly.

Positive Charge	Negative Charge
Glass Rod	Silk Cloth
Fur or woolen cloth	Ebonite, Amber
Woolen Coat	Plastic Seat
Woolen Carpet	Rubber shoes
Nylon or Acetate	Cloth
Dry Hair	Comb

 It is very important to note that the electrification of the body (whether positive or negative) is due to transfer of electrons from one body to another. i.e. If the electrons are transferred from a body, then the deficiency of electrons makes the body positive. If the electrons are gained by a body, then the excess of electrons makes the body negative.

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Some of these questions which may be asked in your Board Examination 2012-2013

Q1: When a plastic comb is passed through dry hair, what type of charge is acquire by comb?

Q2: Does motion of a body affect its charge?

Q3: What is the origin of frictional forces?

Answer these questions in comment box and help your friends