Question

Figure shows the field produced by two point charges +q and -q of equal magnitude but opposite signs (an electric dipole). Find the electric flux through each of the closed surfaces A, B, C and D.

Answer 1

Flux through closed surface A, ${\varphi }_A=\frac{Q_{in}}{{ϵ}_0}=\frac{q}{{ϵ}_0}$
Flux through closed surface B, ${\varphi }_B=\frac{Q_{in}}{{ϵ}_0}=-\frac{q}{{ϵ}_0}$
Flux through closed surface C, ${\varphi }_C=\frac{Q_{in}}{{ϵ}_0}=\frac{q-q}{{ϵ}_0}=0$
Flux through closed surface D, ${\varphi }_D=\frac{Q_{in}}{{ϵ}_0}=0$