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 11 Biotechnology Principles and Processes
Last modified on:4 years agoReading Time:9MinutesExtra Questions for Class 12 Biology Chapter 11 Biotechnology Principles and Processes Q.1. Mention the uses of cloning vector in biotechnology. Ans. Cloning vectors are used for transferring fragments of foreign DNA into a suitable host. They are also used to select recombinants from non-recombinants. Q.2. Identify the reason for selection…
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Extra Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare
Last modified on:4 years agoReading Time:6MinutesExtra Questions for Class 12 Biology Chapter 10 Microbes in Human Welfare Q.1. Name the pests that ladybird, beetle and dragonflies help to get rid of.Ans. Ladybird, beetle and dragonflies control aphids and mosquitoes respectively. Q.2. Why is distillation required for producing certain alcoholic drinks?Ans. Distillation increases the alcohol content in…
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Extra Questions for Class 12 Biology Chapter 9 Strategies for Enhancement in Food Production
Last modified on:4 years agoReading Time:6MinutesExtra Questions for Class 12 Biology Chapter 9 Strategies for Enhancement in Food Production Q.1. A herd of cattle is showing reduced fertility and productivity. Provide one reason and one suggestion to overcome this problem. Ans. Inbreeding depression or continuous inbreeding may be the reason of reduced fertility and productivity. To…
