1. Three conducting spheres of identical radius but made of dissimilar metals copper, gold and silver. One of the spheres (gold) carries excess charge of +Q. If they are all brought into contact with a metal rod and then separated, what will be the charge on all three spheres?
2. A certain charge Q is divided into 2 parts. One is q and the other is Q-q. These two charges are then separated with some distance r. What should be q in terms of Q such that the electrostatic repulsive force among the charges is maximum?
3) 3 particles are on the x-axis. Particle 1 of charge q1 is at x= -a and particle 2 of charge q2 is at x=+a. If the net electrostatic force on particle of charge Q is to be zero, what should the ratio of q1/q2 be if particle 3 is at x = 0.5a?