Question

If the charge $+Q$ is now at the centre of a cube of side $2l$, what is the total flux emerging from all the six faces of the closed surface?

• A. $\frac{Q}{{ϵ}_0}$
• B. $\frac{Q}{2{ϵ}_0}$
• C. $\frac{Q}{4{ϵ}_0}$
• D. $\frac{Q}{6{ϵ}_0}$

Answer 1

The correct option is A $\frac{Q}{{ϵ}_0}$

We know that electric flux through a closed surface is given by total charge inside the curved surface divided by permittivity.

Here, total charge inside the cube is $Q$.

Hence , total flux emerging from whole cube that is from all faces is

$\varphi =\frac{Q}{{ϵ}_o}$

Answer-(A)