The angle between the electric dipole moment of a dipole and the electric field strength due to it on the equatorial line is (in $^{\circ}$)

Two charges each of magnitude $0.01\,C$ and separated by a distance of $0.4\,mm$ constitute an electric dipole. If the dipole is placed in a uniform electric field $\vec{E}$ of $10\,dyne/C$ making a $30^{\circ}$ angle with $\vec{E}$,the magnitude of torque acting on the dipole is:

One end of a spring of negligible unstretched length and spring constant $k$ is fixed at the origin $(0,0)$. $A$ point particle of mass $m$ carrying a positive charge $q$ is attached at its other end. The entire system is kept on a smooth horizontal surface. When a point dipole $\overrightarrow{p}$ pointing towards the charge $q$ is fixed at the origin,the spring gets stretched to a length $\ell$ and attains a new equilibrium position. If the point mass is now displaced slightly by $\Delta \ell \ll \ell$ from its equilibrium position and released,it is found to oscillate at frequency $\frac{1}{\delta} \sqrt{\frac{k}{m}}$. The value of $\delta$ is. . . . . .

The potential at a point due to an electric dipole will be maximum and minimum when the angles between the axis of the dipole and the line joining the point to the dipole are respectively:

$A$ 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:

Mention the direction of the electric dipole moment. Write the $SI$ unit of the electric dipole moment.