How does the electric field due to a point charge vary with the distance r from it? It is proportional to
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \( 1/r^{2} \)
From Coulomb’s law, a point charge \( q \) produces a field of magnitude \( E=|q|/4\pi\varepsilon_0r^{2} \) at distance \( r \). So the field varies as the inverse square of the distance. Doubling \( r \) makes the field one-fourth.
NCERT (2026-27):
Summary – “… Electric field due to a point charge q has a magnitude |q|/4πε0r2; it is radially outwards from q, if q is positive, and radially inwards if q is negative.”
Electric Dipole – “… The electric field due to a dipole therefore falls off, at large distance, faster than like 1/r2 (the dependence on r of the field due to a single charge q).”