Choose the correct statements about electric charge and electric field lines among the following.
A. Coulomb’s law of electric force is valid for point charges only.
B. While dealing with macroscopic charges, we can ignore the quantization of electric charge.
C. Two electric field lines never intersect each other.
D. A charged particle free to move in an electric field always moves along an electric line of force.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A, B and C only
(A) Coulomb’s law of electric force is valid for point charges only. — Correct. The law is stated for point charges, bodies small compared with their separation; for extended bodies the forces of small charge elements are added.
(B) While dealing with macroscopic charges, we can ignore the quantization of electric charge. — Correct. Even \( 1\,\mu\mathrm{C} \) holds a huge number of electronic charges, so charge can be treated as continuous:
\( \displaystyle n = \frac{q}{e} = \frac{1\times10^{-6}\,\mathrm{C}}{1.6\times10^{-19}\,\mathrm{C}} \approx 6\times10^{12} \)
(C) Two electric field lines never intersect each other. — Correct. At a crossing point the field would have two directions, which is impossible.
(D) A charged particle free to move in an electric field always moves along an electric line of force. — Incorrect. A field line gives the direction of the force, not of the velocity; on a curved line the particle’s inertia carries it off the line.
NCERT (2026-27):
Coulomb’s Law – “Coulomb’s law is a quantitative statement about the force between two point charges. When the linear size of charged bodies are much smaller than the distance separating them, the size may be ignored and the charged bodies are treated as point charges.”
Quantisation of Charge – “… Thus, at the macroscopic level, the quantisation of charge has no practical consequence and can be ignored.”
Electric Field Lines – “… (iii) Two field lines can never cross each other. (If they did, the field at the point of intersection will not have a unique direction, which is absurd.)”