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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Numerical Problems Based on Energy in Capacitors for Class 12 Physics
Last modified on:3 years agoReading Time:9MinutesNumerical Problems Based on Energy in Capacitors for Class 12 Physics Q.1. A battery of 10 V is connected to a capacitor of capacity 0.1 F. The battery is now removed and this capacitor is connected to a second uncharged capacitor. If the charge distributes equally on these two capacitors, find…
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Numerical Problems Based on Grouping of Capacitors for Class 12 Physics
Last modified on:3 years agoReading Time:8MinutesNumerical Problems Based on Grouping of Capacitors for Class 12 Physics Q.1. Two capacitors have a capacitance of 5μF when connected in parallel and 1.2 μF when connected in series. Calculate their capacitances. (Ans. 2 μF and 3 μF) Q.2. Calculate the charge supplied by the battery in the arrangement shown…
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Numerical Problems Based on Capacitance of Capacitors for Class 12 Physics
Last modified on:3 years agoReading Time:8MinutesNumerical Problems Based on Capacitance of Capacitors for Class 12 Physics Q.1. Two metallic conductors have net charges of + 70 pC and – 70 pC, which result in a potential difference of 20 V between them. What is the capacitance of the system? (Ans. 3.5 pF) Q.2. A spherical capacitor…
