The nuclear force is:

The correct answer is Option (1) → independent of the nuclear charge

The nuclear force is the force that binds the nucleons (protons and neutrons) in a nucleus. It is much stronger than the Coulomb force, acts only over a few femtometres, and is charge independent: the proton-proton, neutron-neutron and proton-neutron forces are nearly the same.

Option (1) independent of the nuclear charge — Correct. The force between two nucleons does not depend on whether they carry charge, so it is independent of the nuclear charge.

Option (2) are central forces, independent of the spin of the nucleons — Incorrect. The nuclear force is non-central and depends on the spin of the nucleons, so both parts of this option are wrong.

Option (3) short range weak force — Incorrect. It is short range, but it is the strongest of the basic forces, not a weak force.

Option (4) the strong forces between electron and proton bound in a nucleus — Incorrect. It acts between nucleons; electrons are not inside the nucleus and do not feel the nuclear force.

NCERT (2026-27):
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.”