# Two uniformly charged large plane sheets $S_1$ and $S_2$ having charge densities $\sigma_1$ and $\sigma_2(\sigma_1 > \sigma_2)$ are placed at a distance d parallel to each other. A charge $q_0$ is moved along a line of length $a(a < d)$ at an angle $45^{\circ}$ with the normal to $S_1$. Calculate the work done by the electric field.

$W= q_0 E \times \large\frac{a}{\sqrt 2 }$
$\quad= \large\frac{q_0a}{2 \sqrt 2 \in_0}( \sigma_1 - \sigma_2)$