Question

Three charges $q_1=2\times {10}^{-6}C,q_2=3\times {10}^{-6}C$ and $q_3=-6\times {10}^{-6}C$ have been placed as shown in figure. Then, the net electric flux will be minimum for the surface.

• A. $S_1$
• B. $S_2$
• C. $S_3$
• D. Same for all

Answer 1

The correct option is B $S_2$

Charge inside $S_1=q_2+q_2=-3\times {10}^{-6}C$
Charge inside $S_2=q_1+q_2+q_3$
$=-1\times {10}^{-6}C$
Charge inside $S_3=q_1+q_2=5\times {10}^{-6}C$
Charge inside $S_2$ is minimum.
Thus, flux through $S_2$ is minimum.