Which of the following molecules is a polar molecule?

The electric field and the potential of an electric dipole vary with distance $r$ as

What is the angle between the electric dipole moment and the electric field strength due to it on the equatorial line (in $^o$)?

$A$ small electric dipole $\vec{p}_0$,having a moment of inertia $I$ about its center,is kept at a distance $r$ from the center of a spherical shell of radius $R$. The surface charge density $\sigma$ is uniformly distributed on the spherical shell. The dipole is initially oriented at a small angle $\theta$ as shown in the figure. While staying at a distance $r$,the dipole is free to rotate about its center. If released from rest,then which of the following statement$(s)$ is (are) correct? [$\varepsilon_0$ is the permittivity of free space.]
$(A)$ The dipole will undergo small oscillations at any finite value of $r$.
$(B)$ The dipole will undergo small oscillations at any finite value of $r > R$.
$(C)$ The dipole will undergo small oscillations with an angular frequency of $\sqrt{\frac{\sigma p_0}{4 \varepsilon_0 I}}$ at $r = 2R$.
$(D)$ The dipole will undergo small oscillations with an angular frequency of $\sqrt{\frac{\sigma p_0}{100 \varepsilon_0 I}}$ at $r = 10R$.

An electric dipole consisting of two opposite charges of $2 \times 10^{-6} \, C$ each,separated by a distance of $3 \, cm$,is placed in an electric field of $2 \times 10^5 \, N/C$. The maximum torque on the dipole will be:

At any point on the perpendicular bisector of the line joining two equal and opposite charges,which of the following is true?