The energy of the fast neutrons emitted in a nuclear fission reactor is approximately $\qquad$ .

In a nuclear power station,uranium is used for the production of .......

The energy released if hydrogen atoms are combined to form $^{4}_{2}He$ is . . . . . . MeV. (Take binding energies per nucleon of $^{2}H$ and $^{4}_{2}He$ as $1.1$ MeV and $7.2$ MeV, respectively)

How long can an electric lamp of $100\; W$ be kept glowing by the fusion of $2.0\; kg$ of deuterium? Take the fusion reaction as $_{1}^{2} H + _{1}^{2} H \rightarrow _{2}^{3} He + n + 3.27\; MeV$.

Control rods used in nuclear reactors are made of:

When a uranium isotope ${ }_{92}^{235} U$ is bombarded with a neutron,it generates ${ }_{36}^{89} Kr$,three neutrons and: