The strong nuclear force between a neutron and a proton in a zero orbital angular momentum state is denoted by Fnp(r), where r is the separation between them. Similarly, Fnn (r) and Fpp (r) denote the forces between a pair of neutrons and protons, respectively, in zero orbital momentum state. Which of the following is true on average if the inter-nucleon distance is 0.2 fm < r < 2 fm?
1
Fnp is attractive for triplet spin state, and Fnn, Fpp are always repulsive
2
Fnn and Fnp are always attractive and Fpp is repulsive in the triplet spin state
3
Fpp and Fnp are always attractive and Fnn is always repulsive
4
All three forces are always attractive
5
Question Not Attempted