$A$ molecule with a dipole moment $p$ is placed in an electric field of strength $E$. Initially,the dipole is aligned parallel to the field. If the dipole is to be rotated to be anti-parallel to the field,the work required to be done by an external agent is:

An electric dipole is placed at an angle of $30^o$ to a non-uniform electric field. The dipole will experience:

The ratio of electric fields on the axis and at the equator of an electric dipole is

For an electric dipole, if the magnitude of each charge is $10^{-10} \, \text{stC}$ and the distance between them is $1 \, \mathring{A}$, then the dipole moment is:

$A$ dipole comprises two charged particles of identical magnitude $q$ and opposite in nature. The mass $m$ of the positive charged particle is half of the mass of the negative charged particle $(2m)$. The two charges are separated by a distance $l$. If the dipole is placed in a uniform electric field $E$ such that the dipole axis makes a very small angle $\theta$ with the electric field $E$,the angular frequency of the oscillations of the dipole when released is given by:

Three point charges $+q$,$-2q$ and $+q$ are placed at points $(x = 0, y = a, z = 0)$,$(x = 0, y = 0, z = 0)$ and $(x = a, y = 0, z = 0)$ respectively. The magnitude and direction of the electric dipole moment vector of this charge assembly are