The angle between the electric field and the dipole moment at any point on the equatorial plane of an electric dipole is . . . . . . . (in $^{\circ}$)

The figure shows an electric field in which an electric dipole $\overrightarrow{P}$ is placed. Which of the following statements is correct?

An electric dipole is placed at an angle of $30^{\circ}$ in a non-uniform electric field. The electric dipole will experience:

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

$A$ dipole with dipole moment $p$ and moment of inertia $I$ is placed in a uniform electric field $E$. If it is displaced slightly from its stable equilibrium position,the period of oscillation of 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. . . . . .