Match the LIST-I with LIST-II
| LIST-I | LIST-II | ||
| A. | Electric potential in equatorial plane of a dipole | I. | has \( r^{-2} \) dependence |
| B. | Electrostatic potential inside a conductor | II. | zero |
| C. | Electric potential on the axis of a dipole | III. | constant |
| D. | Electric potential due to a point charge | IV. | has \( r^{-1} \) dependence |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A - II, B - III, C - I, D - IV
Compare how each potential depends on the distance \( r \) from the source.
(A) Electric potential in equatorial plane of a dipole — this matches (II) zero. Every point of the equatorial plane is equidistant from \( +q \) and \( -q \), so their potentials cancel.
\( \displaystyle V = \frac{kq}{r_1} - \frac{kq}{r_1} = 0 \)
(B) Electrostatic potential inside a conductor — this matches (III) constant. Inside a conductor \( E = 0 \), so no work is needed to move a charge within it and the potential is the same everywhere, equal to its surface value.
(C) Electric potential on the axis of a dipole — this matches (I) has \( r^{-2} \) dependence. For \( r \) much greater than the dipole length:
\( \displaystyle V = \frac{kp}{r^{2}} \)
(D) Electric potential due to a point charge — this matches (IV) has \( r^{-1} \) dependence.
\( \displaystyle V = \frac{kq}{r} \)
NCERT (2026-27):
Potential Due to an Electric Dipole – “… The potential in the equatorial plane (\( \theta = \pi/2 \)) is zero. … (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.”
Electrostatics of Conductors – “… 4. Electrostatic potential is constant throughout the volume of the conductor and has the same value (as inside) on its surface”