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Small identical balls with equal charges are fixed at vertices of regular 2009- go n with side a. At a certain instant, one of the balls is released & a sufficiently long time interval later, the ball adjacent to the first released ball is freed. The kinetic energies of the released balls are found to differ by K at a sufficiently long distance from the polygon. Determine the charge q of each ball.

Important Questions on Electrostatics

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Beta Question Bank for Engineering: Physics>Chapter 22 - Electrostatics>Exercise-4>Q 9
The electric field in a region is given by E→=E0xli→. Find the charge contained inside a cubical volume bounded by the surfaces x=0, x=a, y=0, y=a, z=0 and z=a. Take E0=5×103 N C−1, l=2 cm and a=1 cm.
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Beta Question Bank for Engineering: Physics>Chapter 22 - Electrostatics>Exercise-4>Q 12
A cavity of radius r is present inside a solid dielectric sphere of radius R, having a volume charge density of ρ. The distance between the centres of the sphere and the cavity is a. An electron e is kept inside the cavity at angle θ=45° as shown. How long will it take to touch the sphere again?

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Beta Question Bank for Engineering: Physics>Chapter 22 - Electrostatics>Exercise-4>Q 14
Positive charge Q is uniformly distributed throughout the volume of a sphere of radius R. A point mass having charge +q and mass m is fired towards the centre of the sphere with velocity v from a point A at distance r (r>R) from the centre of the sphere. Find the minimum velocity v so that it can penetrate R2 distance of the sphere. neglect any resistance other than electric interaction. Charge on the small mass remains constant throughout the motion.
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Beta Question Bank for Engineering: Physics>Chapter 22 - Electrostatics>Exercise-4>Q 15
Electrically charged drops of mercury fall from altitude h into a spherical metal vessel of radius R in the upper part of which there is a small opening. The mass of each drop is m &  charge is Q. What is the number 'n' of last drop that can still enter the sphere.

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Beta Question Bank for Engineering: Physics>Chapter 22 - Electrostatics>Exercise-4>Q 18
Consider the configuration of a system of four charges each of value +q. Find the work done by external agent in changing the configuration of the system from figure i to figure. ii.

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