A charge Q is placed at each of the opposite corners of a square. A charge q is placed at each of the other two corners. If the net electrical force on Q is zero, then Q q equals:

Step-by-step solution

It is given that F _ A + F _ B + F _ D =0 Where F _ A , F _ B and F _ D are the forces applied by charges placed at A, B and D on the charge placed at C . array l F _ B + F _ D =- F _ A | F _ B + F _ D |= 2 KqQ a ² | F _ A |= KQ ² 2 a² 2 KqQ a² =- KQ ² 2 a² Q q =-2 2 array