Electric dipole, field due to dipole, torque in uniform field

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, \(4\times10^{-6}\) C m, is \(\pm9\times10^3\) V.

(Take \(\frac{1}{4\pi\epsilon_0}=9\times10^9\) SI units)

Reason R : \(V=\pm\frac{2P}{4\pi\epsilon_0 r^2}\), 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:

An electric dipole is placed at an angle of \(30^\circ\) with an electric field of intensity \(2\times10^{5}\,\mathrm{N\,C^{-1}}\). It experiences a torque equal to 4 N m. Calculate the magnitude of charge on the dipole, if the dipole length is 2 cm.

Two point charges \(-q\) and \(+q\) are placed at a distance of L, as shown in the figure.

The magnitude of electric field intensity at a distance R (R>>L) varies as :

A dipole is placed in an electric field as shown. In which direction will it move ?

A short electric dipole has a dipole moment of \(16\times10^{-9}\) C m. The electric potential due to the dipole at a point at a distance of 0.6 m from the centre of the dipole, situated on a line making an angle of \(60^\circ\) with the dipole axis is :

\(\left(\frac{1}{4\pi\epsilon_0} = 9\times10^9\ \text{N m}^2/\text{C}^2\right)\)

An electric dipole is placed at an angle of 30° with an electric field intensity \(2\times10^5\) N/C. It experiences a torque equal to 4 N m. The charge on the dipole, if the dipole length is 2 cm, is