Assertion (A): The nuclear force is much stronger than the Coulomb force.
Reason (R): The nuclear force is short-ranged.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
(A) The nuclear force is much stronger than the Coulomb force. — True. Inside the nucleus, the attractive nuclear force has to overcome the Coulomb repulsion between the protons. It can hold the nucleons together only because it is much stronger.
(R) The nuclear force is short-ranged. — True. The force between two nucleons falls rapidly to zero once they are more than a few femtometres apart.
Why R does not explain A?
Range and strength are separate properties. The range tells how far the force reaches. It does not tell how strong the force is within that distance. The Coulomb force has a long range and is still much weaker.
The short range explains the saturation of the nuclear force and the nearly constant binding energy per nucleon. It does not explain the strength of the force.
NCERT (2026-27):
Nuclear Force – “(i) The nuclear force is much stronger than the Coulomb force acting between charges or the gravitational forces between masses. The nuclear binding force has to dominate over the Coulomb repulsive force between protons inside the nucleus.”
Nuclear Force – “(ii) The nuclear force between two nucleons falls rapidly to zero as their distance is more than a few femtometres. This leads to saturation of forces in a medium or a large-sized nucleus, which is the reason for the constancy of the binding energy per nucleon.”