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 the energy released per fission of a ${ }_{92}^{235} U$ nucleus is $200 \text{ MeV}$, the energy released in the fission of $0.1 \text{ kg}$ of ${ }_{92}^{235} U$ in kilowatt-hour is:

The explosive in a Hydrogen bomb is a mixture of ${ }_1 H^2, { }_1 H^3$ and ${ }_3 Li^6$ in some condensed form. The chain reaction is given by:
${ }_3 Li^6 + { }_0 n^1 \rightarrow { }_2 He^4 + { }_1 H^3$
${ }_1 H^2 + { }_1 H^3 \rightarrow { }_2 He^4 + { }_0 n^1$
During the explosion,the energy released is approximately:
[Given: $M(Li^6) = 6.01690 \ amu, M({ }_1 H^2) = 2.01471 \ amu, M({ }_2 He^4) = 4.00388 \ amu$,and $1 \ amu = 931.5 \ MeV$] (in $MeV$)

Which of the following cannot cause fission in a heavy nucleus?

Slowing down of neutrons: In a nuclear reactor,a neutron of high speed (typically $10^{7} \; m s^{-1}$) must be slowed to $10^{3} \; m s^{-1}$ so that it can have a high probability of interacting with isotope $^{235}_{92}U$ and causing it to fission. Show that a neutron can lose most of its kinetic energy in an elastic collision with a light nucleus like deuterium or carbon,which has a mass of only a few times the neutron mass. The material making up the light nuclei,usually heavy water $(D_{2}O)$ or graphite,is called a moderator.

Let $E_1$ and $E_2$ be the binding energies of two nuclei $A$ and $B.$ It is observed that two nuclei of $A$ combine together to form a $B$ nucleus. This observation is correct only if