Which nuclear process occurs in a hydrogen bomb? Or,state the principle of a hydrogen bomb.

If $200 \text{ MeV}$ of energy is released in the fission of one nucleus of ${ }_{92}^{236} U$, the number of nuclei that must undergo fission to release an energy of $1000 \text{ J}$ is

In any fission process,the ratio $\frac{\text{mass of fission products}}{\text{mass of parent nucleus}}$ is

The power obtained in a reactor using $^{235}U$ disintegration is $1000 \text{ kW}$. The mass decay of $^{235}U$ per hour is ............ $\mu g$.

Fission of nuclei is possible because the binding energy per nucleon in them

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.