Heavy water is used as a moderator in a nuclear reactor because

If the binding energy per nucleon of deuteron $({ }_1 H^2)$ is $1.15 \text{ MeV}$ and an $\alpha$-particle has a binding energy of $7.1 \text{ MeV}$ per nucleon,then the energy released per nucleon in the given reaction is ${ }_1 H^2 + { }_1 H^2 \rightarrow { }_2 He^4 + Q$. (in $\text{ MeV}$)

Fast neutrons can easily be slowed down by

The energy released in an atom bomb is obtained from?

What will be the energy released in joule,in the process of fission by $1 \text{ mg}$ of ${ }_{92}^{240} U$? Assume energy release per fission is $200 \text{ MeV}$. [Use Avogadro's number as $6 \times 10^{23}$ and $1 \text{ eV} = 1.6 \times 10^{-19} \text{ J}$]

The energy liberated on complete fission of $1\, kg$ of $_{92}{U^{235}}$ is (Assume $200\, MeV$ energy is liberated on fission of $1$ nucleus).