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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Extra Questions for Class 12 Biology Chapter 15 Biodiversity and Conservation
Last modified on:4 years agoReading Time:8MinutesExtra Questions for Class 12 Biology Chapter 15 Biodiversity and Conservation Q.1. Define biodiversity.Ans. The occurrence of different types of genes, gene pools, species, habitats and ecosystems in a particular place and various parts of earth is called biodiversity. Q.2. What is mass extinction?Ans. Due to natural calamities like volcanic eruptions,…
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Extra Questions for Class 12 Biology Chapter 14 Ecosystem
Last modified on:4 years agoReading Time:11MinutesExtra Questions for Class 12 Biology Chapter 14 Ecosystem Q.1. What is detritus?Ans. Dead organic matter or remains of plant such as leaves, bark, flower and dead remain of animals, including faecal matter constitute detritus. Q.2. Why is the rate of assimilation of energy at the herbivore level called secondary productivity?Ans.…
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Extra Questions for Class 12 Biology Chapter 13 Organisms and Populations
Last modified on:4 years agoReading Time:14MinutesExtra Questions for Class 12 Biology Chapter 13 Organisms and Populations Q.1. Name the interaction between sea anemone and the hermit crab that grows on it.Ans. Commensalism Q.2. Why are green algae not likely to be found in the deepest strata of the ocean?Ans. The wavelength of light at the deepest…
