What is a point dipole?

Which of the following options is a pair of polar molecules?

An electric dipole is placed in an electric field generated by a point charge.

The potential at a point $P$ due to an electric dipole is $1.8 \times 10^5 \, V$. If $P$ is at a distance of $50 \, cm$ from the centre $O$ of the dipole and the line $OP$ makes an angle of $60^{\circ}$ with the positive side of the axial line of the dipole,what is the dipole moment?

In a certain region of space,the electric field is along the $z$-direction throughout. The magnitude of the electric field is,however,not constant but increases uniformly along the positive $z$-direction at the rate of $10^{5} \; N \, C^{-1}$ per meter. What are the force and torque experienced by a system having a total dipole moment equal to $10^{-7} \; C \, m$ in the negative $z$-direction?

The relation between the intensity of the electric field of an electric dipole at a distance $r$ from its centre on its axis and the distance $r$ is . . . . . . . (where $r \gg 2a$)