Q 12-01-149JEE MainJEE Main 2019 (12 Apr, Shift 1)Easy
A point dipole $\vec{p} = -p_0\hat{x}$ is kept at the origin. The potential and electric field due to this dipole on the $y$-axis at a distance $d$ are, respectively: (Take $V = 0$ at infinity)
Answer: (D) $0$, $\dfrac{-\vec{p}}{4\pi\varepsilon_0d^3}$
The $y$-axis is on the dipole's equatorial line. There the potential is zero and the field is antiparallel to the dipole moment:
$$V = 0,\qquad \vec{E} = \frac{-\vec{p}}{4\pi\varepsilon_0d^3}$$
Solution by Sreeraj P, M.Sc Physics