Four identical point charges are fixed at the corners of a square of side kept in air.

PHYSICS · Multi-part · CBSE · Physics · Electrostatic Potential and Capacitance · Electrostatic Potential and Capacitance

Problem

Four identical point charges

+q

are fixed at the corners of a square of side

0.20\,\text{m}

kept in air. (i) Obtain an expression for the electric potential at the centre of the square in terms of

q

and the side

a

. (ii) Calculate the numerical value of the potential at the centre when

q = 5\,\mu\text{C}

. (iii) How much work has to be done in bringing a point charge

-2\,\mu\text{C}

from infinity to the centre of the square? State the sign of the work.