The electric field of an electric dipole at a large distance is proportional to :
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → \( \displaystyle\frac{1}{r^{3}} \)
An electric dipole is a pair of equal and opposite charges \( \pm q \) a small distance \( 2a \) apart. At a large distance the fields of the two charges nearly cancel, and what is left falls one power of \( r \) faster than the field of a single charge.
On the axis and on the equatorial line, for \( r \gg a \):
\( \displaystyle E_{\text{axial}} = \frac{1}{4\pi\varepsilon_0}\,\frac{2p}{r^{3}} \)
\( \displaystyle E_{\text{equatorial}} = \frac{1}{4\pi\varepsilon_0}\,\frac{p}{r^{3}} \)
So at every point far away the dipole field is proportional to \( 1/r^{3} \).
NCERT (2026-27):
The Field of an Electric Dipole – “… Notice the important point that the dipole field at large distances falls off not as 1/r2 but as 1/r3.”