The binding energy per nucleon versus mass number curve is shown in the figure. $W, X, Y$ and $Z$ are four nuclei on the curve. In which process is energy released?

$\gamma$-rays radiation can be used to create an electron-positron pair. In this process of pair production,$\gamma$-rays energy cannot be less than ....... $MeV$.

If $M(A, Z)$,$M_p$,and $M_n$ denote the masses of the nucleus ${}_Z^AX$,proton,and neutron respectively in units of $u$ $(1u = 931.5 \text{ MeV}/c^2)$,and $BE$ represents its binding energy in $\text{MeV}$,then:

The energy equivalent to a mass of $1 \,kg$ is

Assume that the nuclear binding energy per nucleon $(B/A)$ versus mass number $(A)$ is as shown in the figure. Use this plot to choose the correct choice$(s)$ given below.
Figure: $222706-q$
$(A)$ Fusion of two nuclei with mass numbers lying in the range of $1 < A < 50$ will release energy.
$(B)$ Fusion of two nuclei with mass numbers lying in the range of $51 < A < 100$ will release energy.
$(C)$ Fission of a nucleus lying in the mass range of $100 < A < 200$ will release energy when broken into two equal fragments.
$(D)$ Fission of a nucleus lying in the mass range of $200 < A < 260$ will release energy when broken into two equal fragments.

The $Q$-value of a nuclear reaction and kinetic energy of the projectile particle,$K_{p}$,are related as