$A$ 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

Draw the electric field lines for a system of two identical positive charges placed near each other.

$A$ hollow cylinder has a charge $q$ coulomb within it. If $\phi$ is the electric flux in units of volt-meter associated with the curved surface $B$,the flux linked with the plane surface $A$ in units of volt-meter will be:

Which of the following represents the correct path of electric field lines when a metallic sphere is placed in a uniform electric field?

Out of the following statements,which is $NOT$ a characteristic of electric lines of force?

$A$ circular disc of radius $R$ carries surface charge density $\sigma(r) = \sigma_0 \left(1 - \frac{r}{R}\right)$,where $\sigma_0$ is a constant and $r$ is the distance from the center of the disc. Electric flux through a large spherical surface that encloses the charged disc completely is $\phi_0$. Electric flux through another spherical surface of radius $\frac{R}{4}$ and concentric with the disc is $\phi$. Then the ratio $\frac{\phi_0}{\phi}$ is: