The process by which a heavy nucleus splits into light nuclei is known as

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

The disintegration energy $Q$ for the nuclear fission of ${ }^{235} U \rightarrow{ }^{140} Ce+{ }^{94} Zr+n$ is $\_ \text{MeV}$.
Given atomic masses of:
${ }^{235} U: 235.0439 \text{ u}, { }^{140} Ce: 139.9054 \text{ u},$
${ }^{94} Zr: 93.9063 \text{ u}, n: 1.0086 \text{ u},$
Value of $c^2 = 931 \text{ MeV/u}$.

Suppose India had a target of producing by $2020\; AD$, $200,000\; MW$ of electric power, ten percent of which was to be obtained from nuclear power plants. Suppose we are given that, on an average, the efficiency of utilization (i.e., conversion to electric energy) of thermal energy produced in a reactor was $25\%$. How much amount of fissionable uranium would our country need per year by $2020$? Take the heat energy per fission of $^{235}_{92}U$ to be about $200\; MeV$.

In an atomic reactor,the kinetic energy of fast-moving neutrons can be reduced by colliding them with:

$A$ nucleus is bombarded with a high-speed neutron so that the resulting nucleus is a radioactive one. This phenomenon is called: