If in a nuclear fusion process the masses of the fusing nuclei are ${m_1}$ and ${m_2}$ and the mass of the resultant nucleus is ${m_3}$, then

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:
$(A)$ Fusion of two nuclei with mass numbers lying in the range of $1 < A < 100$ will release energy.
$(B)$ Fusion of two nuclei with mass numbers lying in the range of $100 < A < 200$ 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.

In a nuclear reactor, the main purpose of the moderator is to

The average energy of a neutron produced in the fission of ${ }_{92}^{235} U$ is

The fission properties of $_{94}^{239} Pu$ are very similar to those of $_{92}^{235} U$. The average energy released per fission is $180 \; MeV$. How much energy, in $MeV$, is released if all the atoms in $1 \; kg$ of pure $_{94}^{239} Pu$ undergo fission?

$A$ nucleus with mass number $220$ initially at rest emits an $\alpha -$ particle. If the $Q$ value of the reaction is $7.8 \, MeV$ and subsequently after the emission of the $\alpha -$ particle,a photon of energy $1.2 \, MeV$ is also emitted. The kinetic energy of the $\alpha -$ particle is ? .......... $MeV$