Calculate the interaction energy of two balls whose charges `q_(1)` and `q_(2)` are spherically. The distanace between teh centres of the balls is equal to `l`.

Two identical small conducting balls have positive charges q_1 and q_2 respectively. The force between the balls when they are placed at a separation is F. The balls are brought together so that they touch and then put back in their original positions. Prove that the force between the balls now, cannot be less than F.

Two identical small conducting balls have positive charges q_1 and q_2 respectively. The force between the balls when they are placed at a separation is F. The balls are brought together so that they touch and then put back in their original positions. Prove that the force between the balls now, cannot be less than F.

Two similar balls are suspended from a point by two silk thread, each of length l. Each ball of mass m contains q amount of charge. If the angle between the two threads is very small, show that the distance between the centres of the two balls at equilibrium is x=((2q^(2)l)/(mg))^(1//3)

Two concentric spherical shells fo radill R and 2R are given charges Q_(1) and Q_(2) respectively. The surfaces charge densities of the outer surfaces are equal. Determine the ratio Q_(1) : Q_(2) .

A ball of mass m=0.5kg is suspended by a thread and a charge q=0.1muC is supplied when a ball with diameter 5cm and a like charge of same magnitude is brought close to the first ball but below it the tension decreases to 1//3 of its intial value .The distance between centres of the balls is