The electric potential for an electric dipole
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → is zero at mid-point on the line, joining two charges of dipole
Explanation:
For an electric dipole having charges +q and −q separated by distance 2a, the potential at a point on its axial or equatorial line is given by:
$ V = \frac{1}{4\pi \varepsilon_0} \frac{p \cos\theta}{r^2} $
where $ p = q(2a) $ is the dipole moment.
• The potential due to a dipole varies inversely as $ r^2 $, not $ r $. Hence, the first statement is incorrect.
• Electric potential is a scalar quantity. Hence, the second statement is incorrect.
• On the equatorial line (mid-point between charges), potentials due to +q and −q are equal and opposite. Therefore, the net potential is zero. Hence, the third statement is correct.
• The direction of dipole moment and hence the direction of potential is from −q to +q. Hence, the fourth statement is correct.
Correct statements: (C) and (D)