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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Physics MCQs for Class 12 with Answers Chapter 11 Dual Nature of Matter and Radiation
Last modified on:5 years agoReading Time:24MinutesQ.1. Cathode ray consists of(a) photons (b) electrons(c) protons (d) α-particles Answer Answer: (b) Cathode ray consists of electrons Q.2. A discharge takes place between the two electrodes on applying the electric field to the gas in the discharge tube. The cause of this fluorescence was attributed to(a) the radiations which…
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Physics MCQs for Class 12 with Answers Chapter 12 Atoms
Last modified on:5 years agoReading Time:27MinutesQ.1. Balmer series lies in which spectrum?(a) visible(b) ultraviolet(c) infrared(d) partially visible, partially infrared Answer Answer: (b) Q.2. In Bohr model of hydrogen atom, let P.E. represents potential energy and T.E. represents the total energy. In going to a higher level.(a) P. E. decreases, T.E. increases(b) P. E. increases, T.E. decreases(c)…
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Physics MCQs for Class 12 with Answers Chapter 13 Nuclei
Last modified on:5 years agoReading Time:24MinutesMCQ based on Nuclei: Q.1. For a nuclear fusion process, suitable nuclei are(a) any nuclei(b) heavy nuclei(c) lighter nuclei(d) nuclei lying in the middle of periodic table Answer Answer: (c) Q.2. In the uranium radioactive series, the initial nucleus is 92U238 and that the final nucleus is 82Pb206. When uranium nucleus…
