Identify the correct statements from the following :
A. The charge on a body can have any value greater than the charge on an electron or proton.
B. Gauss's theorem is valid for a closed surface of any shape and for any general charge distribution.
C. The net flux through a closed surface due to a charge lying outside the closed surface is zero.
D. Gauss's theorem is applicable to any field which obeys the inverse square law
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → B, C and D only
(A) The charge on a body can have any value greater than the charge on an electron or proton. — Incorrect. Charge is quantised: every charge is an integral multiple of e, \( q = ne \). A value such as 1.5e is not possible.
(B) Gauss's theorem is valid for a closed surface of any shape and for any general charge distribution. — Correct. \( \oint \vec{E}\cdot d\vec{A} = q_{\mathrm{enc}}/\varepsilon_0 \) holds for every closed surface and every distribution; symmetry is needed only to use it easily for finding E.
(C) The net flux through a closed surface due to a charge lying outside the closed surface is zero. — Correct. Every field line from an outside charge that enters the surface also leaves it, so the enclosed charge is zero and so is the net flux.
(D) Gauss's theorem is applicable to any field which obeys the inverse square law — Correct. The result depends on the field falling as \( 1/r^{2} \) while the area of a sphere grows as \( r^{2} \); it holds equally for the gravitational field.
NCERT (2026-27):
Quantisation of Charge – “Experimentally it is established that all free charges are integral multiples of a basic unit of charge denoted by e.”
Gauss’s Law – “… The law implies that the total electric flux through a closed surface is zero if no charge is enclosed by the surface.”
Gauss’s Law – “… (i) Gauss’s law is true for any closed surface, no matter what its shape or size.”
Gauss’s Law – “… (vi) Finally, Gauss’s law is based on the inverse square dependence on distance contained in the Coulomb’s law.”