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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Physics MCQs for Class 12 Chapter 7 Alternating Current with Answers
Last modified on:5 years agoReading Time:28MinutesMCQs based on Alternating Current: Q.1. In general in an alternating current circuit(a) the average value of current is zero(b) the average value of square of the current is zero(c) average power dissipation is zero(d) the phase difference between voltage and current is zero Answer Answer: (a) Q.2. The frequency of…
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Revision Notes For Class 12 Physics Chapter 6 Electromagnetic Induction
Last modified on:5 years agoReading Time:20MinutesMagnetic flux : The number of magnetic lines of force crossing a surface is known as magnetic flux linked with that surface. It is given by, Φ= B. A = BA cosθ, where B is the strength of magnetic field, A is the area of surface and θ is the angle…
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Lami’s Theorem MCQ for NEET
Last modified on:5 years agoReading Time:7MinutesQ.1. Which of the following is true about Lami’s theorem?(a) The theorem is derived based on the cosine rule of trigonometry(b) The theorem is only applicable to regular shaped bodies in equilibrium(c) The theorem is helpful in determining the unknown forces acting at a point for an object in equilibrium.(d) The…
