The physics behind a fusion test reactor is:

The average number of prompt neutrons produced per fission of ${U^{235}}$ is

The operation of a nuclear reactor is said to be critical when the value of the neutron multiplication factor $K$ is:

Which of the following is a nuclear fusion reaction?

The energy released per fission of a nucleus of ${}^{240}X$ is $200 \ MeV$. The energy released if all the atoms in $120 \ g$ of pure ${}^{240}X$ undergo fission is $........ \times 10^{25} \ MeV$. (Given $N_A = 6 \times 10^{23}$)

What is a moderator? Name the material used as a moderator in a nuclear reactor.