Four charges equal to `-Q` are placed at the four corners of a square and a charge q is at its centre. If the system is in equilibrium the value of q is

Four charges equal to -Q are placed at the four corners fo a square and a charge q is at its centre, If the system is in equilibrium the value of q si

Four charges +Q, -Q, +Q, -Q are placed at the corners of a square taken in order. At the centre of the square

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

If a charge q is placed at the centre of the line joining two equal charges Q such that the system is in equilibrium then the value of q is

Four positive charges (2sqrt2-1)Q are arranged at the four corners of a square. Another charge q is placed at the center of the square. Resulting force acting on each corner charge is zero if q is

Three charges each of value q are placed at the corners of an equilateral triangle. A fourth charge Q is placed at the centre of the triangle. If Q = -q :

Three charges, each of value q, are placed at the corners of an equilateral triangle. A fourth charge Q is placed at the centre O of the triangle. (a) If Q = -q , will the charges at corners starts to move towards centre of away from it. (b) For what value of Q at O will the charges remain stationary ?