Intensity of an electric field $E$ due to a dipole,depends on distance $r$ as

The electric field due to a dipole at a distance $r$ on its axis is

Explain the force acting on an electric dipole when it is placed parallel or anti-parallel to a non-uniform electric field.

Which of the following molecules is a polar molecule?

An electric dipole consists of two particles, each of mass $1 \ kg$, separated by $1 \ m$, carrying charges $1 \ \mu C$ and $-1 \ \mu C$ respectively. It is in equilibrium in a uniform electric field of $2 \times 10^4 \ Vm^{-1}$. If it is deflected by a small angle $2^{\circ}$, the minimum time taken by it to come back again to the mean position is (in seconds): (in $\pi$)

Two charges $+q$ and $-q$ are kept at a certain distance apart. Then, at any point on the perpendicular bisector of the line joining the two charges: