Table of Contents
Charging of Insulators

Since charge cannot flow through insulators, neither conduction nor induction can be used to charge, insulators, so in order to charge an insulator friction is used. Whenever an insulator is rubbed against a body exchange of electrons takes place between the two. This results in appearance of equal and opposite charges on the insulator and the other body. Thus the insulator is charged.
For example rubbing of plastic with fur, silk with glass causes charging of these things.
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COULOMB’S LAW
Last modified on:3 years agoReading Time:18MinutesCOULOMB’S LAW: Two point electric charges q1 and q2 at rest, separated by a distance r exert a force on each other whose magnitude is given by If between the two charges there is free space then Where ε0 is the absolute electric permittivity of the free space and ε0 =…
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If we comb our hair on a dry day and bring the comb near small pieces of paper, the comb attracts the pieces, why?
Last modified on:4 years agoReading Time:2Minutes If we comb our hair on a dry day and bring the comb near small pieces of paper, the comb attracts the pieces, why? Answer: This is an example of frictional electricity and induction. When we comb our hair, it gets positively charged by rubbing. When the comb is brought…
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Can two similarly charged bodies attract each other?
Last modified on:4 years agoReading Time:1Minute Yes, when the charge on one body Q is much greater than that on the other q and they are close enough to each other so that force of attraction between Q and induced charge on the other exceeds the force of repulsion between Q and q. However, two similar…
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Extra Questions For Class 9 Science Chapter 9 Force and Laws of Motion
Last modified on:5 years agoReading Time:18MinutesExtra Questions For Class 9 Science Chapter 9 Force and Laws of Motion Very Short Answer Type Questions (One Mark Each) Q.1. Give the net force acting on a body at rest. Answer Ans. Net force acting on a body at rest is zero. Q.2. State the meaning of balanced force.…
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Extra Questions For Class 9 Science Chapter 7 Diversity in living organisms
Last modified on:5 years agoReading Time:15MinutesExtra Questions For Class 9 Science Chapter 7 Diversity in living organisms Very Short Answer Type Questions (One Mark Each) Q.1. What is classification of organisms? Answer Ans. Arrangement of organisms into groups or sets on the basis of similarities and differences is termed classification. Q.2. Which organisation state set rule…
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Extra Questions For Class 9 Science Chapter 3 Atoms and Molecules
Last modified on:5 years agoReading Time:12MinutesExtra Questions For Class 9 Science Chapter 5 Fundamental Unit of Life Very Short Answer Type Questions (One Mark Each) Q.1. What is Avogadro’s constant ? Answer Ans. Avogadro’s constant is the number of particles (atoms, ions or molecules) present in mole of the substance. Its value is 6.022 x 1023.…
