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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NCERT Solution For Class 12 Physics Chapter 11 Dual Nature of radiation and matter
Last modified on:5 years agoReading Time:77MinutesQuestion 11.1: Find the (a) maximum frequency, and (b) minimum wavelength of X-rays produced by 30 kV electrons. ANSWER: Potential of the electrons, V = 30 kV = 3 × 104 V Hence, energy of the electrons, E = 3 × 104 eV Where, e = Charge on an electron = 1.6 × 10−19 C (a)Maximum frequency produced by the X-rays = ν The energy of the electrons is…
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NCERT Solutions For Class 12 Physics Chapter 8 Electromagnetic Waves
Last modified on:5 years agoReading Time:28Minutes1.(a) Figure 8.6 shows a capacitor made of two circular plates each of radius 12 cm, and separated by 5.0 cm. The capacitor is being charged by an external source (not shown in the figure). The charging current is constant and equal to 0.15A. Calculate the capacitance and the rate of change…
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NCERT Solutions for CBSE Class 12 Physics ‒ Chapter 1: Electric Charges and Fields
Last modified on:5 years agoReading Time:59MinutesQuestion1.1: What is the force between two small charged spheres having charges of 2 × 10–7 C & 3 × 10–7 C placed 30 cm apart in air? Solution1.1: Given: Q1= 2 × 10-7 C Q2 = 3 × 10-7 C r = 30 × 10-2 m We know, F = (Q1 Q2)/(4 π εo r2 ) Substituting the given values, we get…
