Question

At the centre of a cubical box $+Q$ charge is placed. The value of total flux that is coming out of each face is :

• A. $Q/{\epsilon }_0$
• B. $Q/3{\epsilon }_0$
• C. $Q/4{\epsilon }_0$
• D. $Q/6{\epsilon }_0$

Answer 1

The correct option is D $Q/6{\epsilon }_0$

When $+Q$ charge is placed inside cube
total flux coming out of cube $=\frac{Q}{{ϵ}_0}\left(gausslaw\right)$
As all faces are symmetrically placed around the cube
flux coming from each face $=\frac{Q}{6{ϵ}_0}$