Draw a plot of potential energy of a pair of nucleons as a function of their separation. Mark the regions where the nuclear force is repulsive. Write any two characteristic feature of nuclear forces.

Define the terms binding energy for a nucleus and state the relation between the binding energy and mass defect.In nuclear reaction the $B.E$ per nucleon of the product nucleus/ nuclei is more than that for the original nucleus/nuclei. Is the nuclear reaction exothermic or endothermic in nature? Justify your choice.

Estimate the amount of energy in electron volt that will be available if $1 \mathrm{amu}$ of mass is converted into energy.

Given $1 \mathrm{amu}=1.6605\times {10}^{-24} \mathrm{gm}, 1 \mathrm{eV}=1.604\times {10}^{-12}\mathrm{erg}$