The binding energy per nucleon for ${}_1^2H$ and ${}_2^4He$ are $1.1 \; MeV$ and $7.1 \; MeV$ respectively. The energy released in $MeV$ when two ${}_1^2H$ nuclei fuse to form one ${}_2^4He$ nucleus is:

Calculate the height of the potential barrier for a head-on collision of two deuterons. (Hint: The height of the potential barrier is given by the Coulomb repulsion between the two deuterons when they just touch each other. Assume that they can be taken as hard spheres of radius $2.0 \; fm$.)

The binding energies of nuclei $X$ and $Y$ are $E_1$ and $E_2$ respectively. Two atoms of $X$ fuse to give one atom of $Y$ and an energy $Q$ is released. Then:

The binding energy per nucleon for deuteron $(_1^2H)$ and helium $(_2^4He)$ nuclei are $1.1 \, MeV$ and $7 \, MeV$ respectively. Calculate the energy released in $MeV$ when two deuteron nuclei fuse to form a helium nucleus.

The energy released if hydrogen atoms are combined to form $^{4}_{2}He$ is . . . . . . MeV. (Take binding energies per nucleon of $^{2}H$ and $^{4}_{2}He$ as $1.1$ MeV and $7.2$ MeV,respectively)

Calculate and compare the energy released by
$(a)$ fusion of $1.0 \; kg$ of hydrogen deep within the Sun and
$(b)$ the fission of $1.0 \; kg$ of $^{235} U$ in a fission reactor.