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:5 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:5 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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Concepts of Physics Ch-15 Wave Motion and Wave On a String (SA)
Last modified on:5 years agoReading Time:6Minutes You are walking along seashore and a mild wind is blowing. Is the motion of air a wave motion? Solution: No, in wave motion there is no actual transfer of matter but transfer of energy between the points where as when wind blows air particles moves with it. The radio…
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Concepts of Physics Ch-13 Fluid Mechanics (SA)
Last modified on:5 years agoReading Time:20Minutes1. Is it always true that the molecules of a dense liquid are heavier than the molecules of a lighter liquid ? Solution: Density is defined as mass per unit volume. It tells how closely packed are the molecules inside an object. When molecules are tightly packed, we say that the…
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Concepts of Physics Ch-12 SHM (SA)
Last modified on:5 years agoReading Time:13Minutes 1. A person goes to bed at sharp 10:00 pm every day. Is it an example of periodic motion? If yes, what is the time period? If no, why? Solution: No. As motion is a change in position of an object with respect to time or a reference point, it…
