$A$ charged body has an electric flux $\phi$ associated with it. The body is now placed inside a metallic container. The flux $\phi$ outside the container will be

The number of electric lines that emerge from a finite charge $+q$ is . . . . . . .

$A$ uniformly charged conducting sphere of diameter $3.5 \ cm$ has a surface charge density of $20 \ \mu C \ m^{-2}$. The total electric flux leaving the surface of the sphere is nearly:
[permittivity of free space,$\epsilon_0 = 8.85 \times 10^{-12} \ SI \ unit$]

Four dipoles having charge $\pm e$ are placed inside a sphere. The total flux of $\vec{E}$ coming out of the sphere is

$A$ sphere of radius $R$ and charge $Q$ is placed inside an imaginary sphere of radius $2R$ whose center coincides with the given sphere. The flux related to the imaginary sphere is

The electric field in a region is given by $\overrightarrow{E} = (\frac{3}{5} E_{0} \hat{i} + \frac{4}{5} E_{0} \hat{j}) \, N/C$. The ratio of the flux of this field through a rectangular surface of area $0.2 \, m^{2}$ (parallel to the $y-z$ plane) to that through a surface of area $0.3 \, m^{2}$ (parallel to the $x-z$ plane) is $a : b$,where $a = \dots$ [Here $\hat{i}, \hat{j}$ and $\hat{k}$ are unit vectors along the $x, y$ and $z$-axes respectively].