Identify the correct statements.
(A) Electric charge is quantized.
(B) Electric charge on any object is always an integral multiple of e.
(C) The coulomb force is weaker than the gravitational force.
(D) The coulomb force is a conservative force.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → (A), (B) and (D) only
(A) Electric charge is quantized. — Correct. Charge exists only in whole-number units of the elementary charge \( e = 1.6\times10^{-19}\,\mathrm{C} \).
(B) Electric charge on any object is always an integral multiple of e. — Correct. This is the statement of quantisation itself: \( q = ne \), with \( n \) an integer, because charge is transferred only as whole electrons.
(C) The coulomb force is weaker than the gravitational force. — Incorrect. The Coulomb force is far stronger: between two protons the ratio of the electric to the gravitational force is about \( 10^{36} \).
(D) The coulomb force is a conservative force. — Correct. It is a central force, so the work it does depends only on the end points, and a potential energy can be defined for it.
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. Thus charge q on a body is always given by \( q = ne \) where n is any integer, positive or negative.”
Coulomb’s Law – “… The actual values of these forces between two protons inside a nucleus (distance between two protons is ~ 10-15 m inside a nucleus) are Fe ~ 230 N, whereas, FG ~ 1.9 × 10–34 N. The (dimensionless) ratio of the two forces shows that electrical forces are enormously stronger than the gravitational forces.”
Introduction – “… Spring force and gravitational force are examples of conservative forces. Coulomb force between two (stationary) charges is also a conservative force.”