Question

A point charge $Q$ is located at the centre of a cube of edge length $a$. The total electric flux through one of the face of the cube is

• A. $\frac{Q}{{\epsilon }_o}$
• B. $\frac{Q}{3{\epsilon }_o}$
• C. $\frac{Q}{6{\epsilon }_o}$
• D. $\frac{3Q}{{\epsilon }_o}$

Answer 1

The correct option is C $\frac{Q}{6{\epsilon }_o}$

Flux will be same for all faces
So applying Gauss law for cube
$\int \overrightarrow{E.}\overrightarrow{ds}$= $\frac{q_{enclosed}}{{\epsilon }_o}$ (total flux)
Flux through each face = $\frac{Q}{6{\epsilon }_o}$