$A$ nuclear reactor with $40\%$ efficiency produces $10^{14}$ fissions per second. Each fission releases $250 \text{ MeV}$ of energy. The power output of the reactor is ......... $W$.

The binding energy of deuteron $_1^2H$ is $1.112 \, MeV$ per nucleon and an $\alpha$-particle $_2^4He$ has a binding energy of $7.047 \, MeV$ per nucleon. Then in the fusion reaction $_1^2H + _1^2H \to _2^4He + Q$,the energy $Q$ released is ........ $MeV$.

If $5 \ mg$ of ${}^{235}U$ is completely destroyed in an atom bomb, then the approximate total energy released is (given that the energy released per fission is $200 \ MeV$).

Energy released when two deuterons $\left({ }_1 H ^2\right)$ fuse to form a helium nucleus $\left({ }_2 He ^4\right)$ is $:$
(Given $:$ Binding energy per nucleon of ${ }_1 H ^2=1.1 \ \text{MeV}$ and binding energy per nucleon of ${ }_2 He ^4=7.0 \ \text{MeV}$) (in $\text{MeV}$)

What was the fissionable material used in the bomb dropped at Nagasaki (Japan) in the year $1945$?

$A$ nucleus ${}^{220}X$ at rest decays by emitting an $\alpha$-particle. If the kinetic energy of the daughter nucleus is $0.2 \, MeV$,the $Q$-value of the reaction is ........ $MeV$.