A hollow cylinder has charge ' $q$ ' $C$ within it. If ' $\phi$ ' is the electric flux associated with the curved

' $n$ ' small drops of same size are charged to ' $V$ ' volt each. If they coalesce to form a single large drop, then its potential will be

Two point charges $+8 q$ and $-2 q$ are located at $x=0$ and $x=\mathrm{L}$ respectively. The location of a point on the $x$-axis from the origin, at which the net electric field due to these two point charges is zero is

When the dielectric is placed in an external electric field, the electric field inside the dielectric is