Question

Four charges −q, −q, +q and +q are placed at the corners of a square of side 2 L is shown in figure. The electric potential at point A midway between the two charges +q and +q is:

Options

• `1/(4 pi epsilon_0) (2q)/L(1 - 1/sqrt5)`

• `1/(4 pi epsilon_0) (2q)/L(1 + 1/sqrt5)`

• `1/(4 pi epsilon_0) q/(2L)(1 - 1/sqrt5)`

• zero

Answer 1

`bb(1/(4 pi epsilon_0) (2q)/L(1 - 1/sqrt5))`

Explanation:

Electric potential due to two +q charges

= `1/(4 pi epsilon_0) (2q)/L`

Electric potential due to two −q charges

= `1/(4 pi epsilon_0) (-2q)/(sqrt5 L)`

Total potential at A = `1/(4 pi epsilon_0) (2q)/L(1 - 1/sqrt5)`