Question

A charge Q is placed at a distance a/2 above the centre of a horizontal, square of edge , a as shown in figure(30-E1). Find the flux of the electric field through the square surface.

Answer 1

Given, a charge is placed on a plane surface with area $a^2$

About $\frac{a}{2}$ from it's centre

Assumption : Let us assume that the given plane forms a surface of imaginary cube than the charge is found to be at the centre of the cube.

Hence flux through the surface

$=\frac{Q}{{\in }_0}\times \frac{1}{6}=\frac{Q}{6{\in }_0}$