PYQ NEET- Electric Charges And Fields L-5

Question: What is the flux through a cube of side $a$ if a point charge of $q$ is at one of its corner?#

A) $\frac{2 q}{\varepsilon_0}$

B) $\frac{q}{8 \varepsilon_0}$

C) $\frac{q}{\varepsilon_0}$

D) $\frac{q}{2 \varepsilon_0} 6 a^2$

Answer: $\frac{q}{8 \varepsilon_0}$#

Sol:#

Concept According to Gauss’s law, the electric flux through a closed surface is equal to $\frac{1}{\varepsilon_0}$ times the net charge enclosed by the surface.

As the charge enclosed $=q / 8$

So, electric flux $=\frac{q_{\text {enclosed }}}{\varepsilon_0} \Rightarrow \phi=\frac{q}{8 \varepsilon_0}$