Question

Eight point charges (can be assumed as small spheres uniformly charged and their centres at the corner of the cube) having values q each are fixed at vertices of a cube. The electric flux through square surface ABCD of the cube is

• A. $\frac{q}{24{\in }_0}$
• B. $\frac{q}{12{\in }_0}$
• C. $\frac{q}{6{\in }_0}$
• D. $\frac{q}{8{\in }_0}$

Answer 1

The correct option is D $\frac{q}{8{\in }_0}$

Using Gauss law we said that,

$\varphi =\frac{q}{{ϵ}_0}$

Since, all the c/s are in the $8$ corners, Then,

$\varphi =\frac{1}{8}\frac{q}{{ϵ}_0}$