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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Lenz’s law
Last modified on:5 years agoReading Time:4MinutesWhat is Lenz’s Law? This law gives us the direction of induced emf. According to this law, the direction of induced emf in a circuit is such that it opposes the change in magnetic flux responsible for its production. Lenz’s law is in accordance with the principle of conservation of energy.…
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Magnetic Flux
Last modified on:5 years agoReading Time:3MinutesWhat is Magnetic Flux? Flux is basically count of number of lines crossing a surface. The number of magnetic field lines crossing a surface is known as magnetic flux linked with that surface. Consider a closed curve enclosing an area A (as shown in the figure). Let there be a uniform…
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Electromagnetic Induction
Last modified on:5 years agoReading Time:4MinutesWhat is Electromagnetic Induction? It was discovered by Michael Faraday in 1831. It is the phenomenon of generating an emf by changing the number of magnetic field lines (i.e. magnetic flux) associated with the circuit. We have studied that moving charges or current produces magnetic field. Then normally we get a doubt whether…
