Four equal charges `Q` are placed at the four corners of a square of each side is 'a'. Work done in removing a charge `-Q` from its centre to infinity is

Three equal charges Q are placed at the three corners of an equilateral triangle of side length a. Work done in shifting a charge q from infinity to the centroid of the triangle is

Four identical point charges q are placed at four corners of a square of side a. Find the potential energy of the charge system. .

Equal charges Q are placed at the four corners A, B, C, D of a square of length a. The magnitude of the force on the charge at B will be

Equal charges q are placed at the four corners A,B,C,D of a square of length a . The magnitude of the force on the charge at B will be

Four charges Q-Q, Q-Q are placed at the corners of a square as shown . The potential is zero at points

Equal charges q are placed at the three corners B, C, D of a square ABCD of side 'a'. The ratio of potential at A to centre O is

Four point charges are placed at the corners of a square ABCD of side 10 cm, as shown in figure. The force on a charge of 1muC placed at the centre of square is

Four bodies each of mass m are placed at the different corners of a square of side a. find the work done on the system to take any one budy to infinity.