A point $B$ lies on the perpendicular bisector of an electric dipole of dipole moment $\overrightarrow{p}$. The distance of $B$ from the dipole is $r$ ($r$ is much larger than the size of the dipole). The electric intensity at $B$ is proportional to

$S_1,S_2,S_3$ are three concentric spherical shells, as shown in figure. $S_1$ and $S_2$ have charge $4 Q$ and $8 Q$ respectively, whereas $S_3$ is uncharged. Find the ratio of the flux passing through $S_1$ to that through $S_3$

The flux through the hemispherical surface in the figure shown below is