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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MCQ based on Kepler’s Law
Last modified on:4 years agoReading Time:9MinutesOne of the greatest ideas proposed in human history is the fact that the earth is a planet, among the other planets, that orbits the sun. Johannes Kepler discovered three empirical laws by using the data on planetary motion: Law of Orbits: Each planet moves in an elliptical orbit, with the…
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Physics MCQs for Class 12 Chapter 9 Ray Optics and Optical Instruments
Last modified on:2 years agoReading Time:10MinutesPhysics MCQs for Class 12 Chapter 9 Ray Optics and Optical Instruments Here we are providing MCQ Questions for Class 12 Physics Chapter 9 Ray Optics and Optical Instrument. Q.1. Which of the following colour of white light deviated most when passes through a prism?(a) Red light(b) Violet light(c) Yellow light(d)…
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Physics MCQs for Class 12 Chapter 8 Electromagnetic Waves
Last modified on:5 years agoReading Time:36MinutesMCQs on Class 12 Physics Chapter 8 Electromagnetic Waves Q.1. In electromagnetic waves the phase difference between electric and magnetic field vectors are(a) zero(b) 𝜋/4(c) 𝜋/2(d) π Answer Answer: (a) Electric and magnetic field vectors always vary in same phase. Q.2. Which of the following has minimum wavelength? (a) Blue light(b) γ-rays(c) infrared…
