Question

Explain attraction and repulsion force between charge with an example.

Answer 1

Hint: In the field of electromagnetism, it has been seen that like charges (either positive-positive or negative-negative) repel each and unlike charges (positive-negative or negative-positive) attract each other.

Complete answer:
All electric charges exert a force on other charges known as the Coulomb’s force. Charges which are of the same kind, that are either positive-positive or negative-negative exert a repulsive force on each other whereas charges which are opposite in nature, that is, either positive-negative or negative-positive attract each.
This concept has also been made popular by its usage in other matters and in conversational language by the phrase ‘Opposites attract’ and ‘Like repels like.’
Let us consider an example, when a plastic comb is run through our hair, the electrons in our hair (which are negative charge carriers) get transferred to the comb. Hence, the comb has an excess of electrons and hence an excess of negative charge. Thus, it becomes a negatively charged body.
When this comb is brought near bits of paper, it exerts a force of attraction on the protons in the paper and repels the electrons, thus pushing them to the side away from the comb. This happens so fast, that this quick uneven distribution of charge results in a net force of attraction on the paper bits and they jump up to the comb.

Note:
Students must keep in mind that rubbing two items like glass and silk or plastic and hair, together usually results in a transfer of electrons between the bodies and leads to one of them ending up positively charged (the one that has lost electrons) and the other (the one that has gained electrons) to be negatively charged.