$A$ neutral ammonia $(NH_3)$ molecule in its vapour state has an electric dipole moment of magnitude $5 \times 10^{-30} \ C \cdot m$. How far apart are the molecule's centres of positive and negative charge?

The figure shows electric field lines in which an electric dipole $p$ is placed as shown. Which of the following statements is correct?

Two short electric dipoles are placed as shown. The energy of electric interaction between these dipoles will be

Write the equation for the electric field produced by an electric dipole at a point on its equatorial line,given the condition $r >> a$ (where $r$ is the distance from the center and $2a$ is the dipole length).

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: The potential $(V)$ at any axial point, at $2 \ m$ distance $(r)$ from the centre of the dipole of dipole moment vector $\vec{P}$ of magnitude $4 \times 10^{-6} \ C \ m$, is $\pm 9 \times 10^3 \ V$.
(Take $\frac{1}{4 \pi \epsilon_0} = 9 \times 10^9 \ SI$ units)
Reason $R$: $V = \pm \frac{1}{4 \pi \epsilon_0} \frac{P}{r^2}$, where $r$ is the distance of any axial point, situated at $2 \ m$ from the centre of the dipole.
In the light of the above statements, choose the correct answer from the options given below:

The electric field intensity at a point on the axis of an electric dipole in air is $4 \text{ NC}^{-1}$. Then the electric field intensity at a point on the equatorial line which is at a distance equal to twice the distance on the axial line and if the dipole is in a medium of dielectric constant $4$ is