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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Human Ear
Last modified on:4 years agoReading Time:3MinutesHuman Ear The human ear, like that of other mammals, contains sense organs that serve two quite different functions: that of hearing and that of head and eye movements. Anatomically, the ear has three distinguishable parts: the outer, middle, and inner ear. How Human Ear Works? Different sounds produced in our surroundings are collected by…
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Numericals for Class 9 Science Chapter 12 Sound
Last modified on:3 years agoReading Time:14MinutesNumericals for Class 9 Science Chapter 12 Sound Q.1. A boy hears an echo of his own voice from a distant hill after 1 s. the speed of sound is 340m/s. What is the distance of the hill from the boy? Q.2. An engine is approaching a hill at constant speed.…
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Problems Based on Class 9 Science Chapter 10 Gravitation
Last modified on:4 years agoReading Time:6Minutes Q.1. An object weighs 10N when measured on the surface of the earth. What would be its weight when measured on the surface of the Moon? Q.2. Mass of an object is 10kg. What is its weight on Earth? Q.3. What is the mass of an object whose weight is…
