Match List-I with List-II
| List-I | List-II |
| Quantity | Variation with distance |
| (A) Electric field due to a point charge | (I) Inversely proportional to the cube of the distance |
| (B) Electric potential due to a point charge | (II) Inversely proportional to the square of the distance |
| (C) Electric field due to uniformly charged infinite plane sheet | (III) Inversely proportional to the distance |
| (D) Electric field due to an electric dipole | (IV) Independent of the distance |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A) - (II), (B) - (III), (C) - (IV), (D) - (I)
How a field or potential falls with distance \( r \) depends on the shape of the charge distribution.
(A) Electric field due to a point charge — this matches (II) Inversely proportional to the square of the distance. The field lines spread over a sphere of area \( 4\pi r^{2} \).
\( \displaystyle E = \frac{q}{4\pi\varepsilon_0\,r^{2}} \)
(B) Electric potential due to a point charge — this matches (III) Inversely proportional to the distance. The potential is the work per unit charge in bringing a test charge from infinity.
\( \displaystyle V = \frac{q}{4\pi\varepsilon_0\,r} \)
(C) Electric field due to uniformly charged infinite plane sheet — this matches (IV) Independent of the distance. The field lines stay parallel, so the field is the same at every distance.
\( \displaystyle E = \frac{\sigma}{2\varepsilon_0} \)
(D) Electric field due to an electric dipole — this matches (I) Inversely proportional to the cube of the distance. The two opposite charges partly cancel, so at large distance the field falls one power faster than for a point charge.
\( \displaystyle E \propto \frac{p}{4\pi\varepsilon_0\,r^{3}} \)
NCERT (2026-27):
Potential Due to an Electric Dipole – “… Further, the field falls off, at large distance, not as 1/r2 (typical of field due to a single charge) but as 1/r3.”
Potential Due to an Electric Dipole – “… (ii) The electric dipole potential falls off, at large distance, as 1/r2, not as 1/r, characteristic of the potential due to a single charge.”
Field Due to a Uniformly Charged Infinite Plane Sheet – “… Note that the above application of the Gauss’ law has brought out an additional fact: E is independent of x also.”