$A$ hollow cylinder has a charge of $q$ $C$ within it. If $\phi$ is the electric flux associated with the curved surface $B$,the flux linked with the plane surface $A$ will be

The electric flux from a cube of edge $l$ is $\phi$ for an enclosed charge. If the edge of the cube is made $\frac{2}{3} l$ and the charge enclosed in the cube is doubled,then the electric flux value will be

Identify the $WRONG$ statement in the case of electric field lines.

An infinitely long uniform line charge distribution of charge per unit length $\lambda$ lies parallel to the $y$-axis in the $y-z$ plane at $z=\frac{\sqrt{3}}{2} a$ (see figure). If the magnitude of the flux of the electric field through the rectangular surface $A B C D$ lying in the $x-y$ plane with its center at the origin is $\frac{\lambda L }{ n \varepsilon_0}$ (where $\varepsilon_0$ is the permittivity of free space),then the value of $n$ is

$C_1$ and $C_2$ are two hollow concentric cubes enclosing charges $2Q$ and $3Q$ respectively as shown in the figure. The ratio of electric flux passing through $C_1$ and $C_2$ is:

Assertion : Electric lines of force never cross each other.
Reason : Electric field at a point superimpose to give one resultant electric field.