Petency Based Questions
Petency Based Questions
Petency Based Questions
18. An Oil drop of mass ‗m‘ and charge –q is to be held stationary in the
gravitational field of the earth. What is the magnitude and direction
of the electrostatic field required for this purpose?
19. Two charges, each of + 16 μC, are placed along a line at a distance
r apart. A third charge .Q is placed between them. Determine the
position and value of Q so that the system is in equilibrium.
20. ABC is an equilateral triangle of side 10 m. D is the mid-point of BC.
Charge + 100 μC, -- 100 μC and + 75 μC are placed at B, C and D
respectively. What is the force experienced by a1 C positive charge
placed at A?
21. An ‘atom’ was earlier assumed to be a sphere of radius a having a
positively charged point nucleus of charge +Ze at its centre. This
nucleus was believed to be surrounded by a uniform density of
negative charge that made the atom neutral as a whole.
Use this theorem to find the electric field of this ‘atom’ at a distance
r (r<a) from the centre of the atom.