The force between a neutron and a proton are
A. Weak
B. Gravitational
C. Nuclear
D. Colombian
E. Electromagnetic
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → B and C only
A neutron has mass but no charge, while a proton has mass and a positive charge. So only forces that act between masses or between nucleons can act between them.
(A) Weak — Not counted. The force that binds a neutron and a proton is the nuclear force, which is much stronger than the Coulomb force; it is not a weak force.
(B) Gravitational — Acts. Both particles have mass, so they attract each other gravitationally, although this force is extremely small.
(C) Nuclear — Acts. The nuclear force acts between any two nucleons (n-n, p-p and n-p) and is nearly the same for all pairs; it is what holds the neutron and proton together in a nucleus.
(D) Colombian — Does not act. The Coulomb force needs both particles to be charged, and the neutron is neutral.
(E) Electromagnetic — Does not act. For the same reason: the neutron carries no charge.
The forces are B and C, which is Option (4).
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.”
Nuclear Force – “… (iii) The nuclear force between neutron-neutron, proton-neutron and proton-proton is approximately the same. The nuclear force does not depend on the electric charge.”