The masses of neutron, proton and deuteron in amu are $1.00893$, $1.00813$ and $2.01473$, respectively. The packing fraction of the deuteron in amu is

Assertion : Binding energy (or mass defect) of hydrogen nucleus is zero.
Reason : Hydrogen nucleus contains only one nucleon.

If the speed of light were $2/3$ of its present value,the energy released in a given atomic explosion will be decreased by a fraction:

The binding energy per nucleon of ${ }_5 B ^{10}$ is $8.0 \,MeV$ and that of ${ }_5 B ^{11}$ is $7.5 \,MeV$. The energy required to remove a neutron from ${ }_5 B ^{11}$ is .......... $MeV$.

The deuteron is bound by nuclear forces just as the $H$-atom is made up of a proton and an electron bound by electrostatic forces. If we consider the force between the neutron and proton in a deuteron as given in the form of a Coulomb potential but with an effective charge $e'$: $F = \frac{1}{4\pi \epsilon_0} \frac{e'^2}{r^2}$,estimate the value of $(e'/e)$ given that the binding energy of a deuteron is $2.2 \text{ MeV}$.

If the binding energy per nucleon in $Li^7$ and $He^4$ nuclei are respectively $5.60 \ MeV$ and $7.06 \ MeV$, then the energy of the reaction $Li^7 + p \to 2He^4$ is ......... $MeV$.