The principle of controlled chain reaction is used in

What is the energy released by the fission of $1 \, g$ of $U^{235}$?

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

An $\alpha$-particle of energy $E$ is liberated during the decay of a nucleus of mass number $236$. The total energy released in this process is

Which one of the following nuclear reactions is a source of energy in the sun?

What are control rods in a nuclear reactor?