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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Class 10 Science Magnetic Effects of Electric Current (Solved Assignment-01)
Last modified on:5 years agoReading Time:14MinutesVery Short Answer Type Questions: Question 1: State any two properties of magnetic field lines. Solution : Properties of magnetic field lines: (i) The magnetic field lines originate from the north pole of a magnet and end at its south pole. (ii) The strength of magnetic field is indicated by the…
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Android Smartphone Touch Screen
Last modified on:5 years agoReading Time:3MinutesSmartphone touch screens are capacitive which do not use the pressure of the finger to create a change in the flow of electricity. Instead, they work with anything that holds an electrical charge including human skin. (Yes, we are comprised of atoms with positive and negative charges.) Capacitive touch screens are…
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Magnetic field at the centre of a bar magnet is very weak. Why?
Last modified on:5 years agoReading Time:2MinutesWe can divide a bar magnet into a large number of tiny bar magnets. Evaluate, the magnetic field as the superposition of the contributions of all small aligned magnets present in the bar. For a point near the centre of the bar, the magnetic field is very small because the contributions…
