Energy released in the fission of a single ${ }_{92} U^{235}$ nucleus is $200 \ MeV$. The fission rate of a ${ }_{92} U^{235}$ fuelled reactor operating at a power level of $32 \ kW$ is:

In the nuclear fission of one nucleus of $U^{235}$,the energy released is $188 \text{ MeV}$. The energy released in the nuclear fission of $235 \text{ g}$ of $U^{235}$ is nearly (Avogadro number $= 6.02 \times 10^{23} \text{ mol}^{-1}$)

Light energy emitted by stars is due to

The main source of solar energy is

This question contains Statement-$1$ and Statement-$2$. Of the four choices given after the statements,choose the one that best describes the two statements.
Statement-$1$: Energy is released when heavy nuclei undergo fission or light nuclei undergo fusion.
Statement-$2$: For heavy nuclei,binding energy per nucleon increases with increasing $Z$,while for light nuclei,it decreases with increasing $Z$.

$A$ $\gamma$-ray photon creates an electron-positron pair. If the rest mass energy of an electron is $0.51 \, MeV$ and the total kinetic energy of the electron-positron pair is $0.78 \, MeV$,then the energy of the $\gamma$-ray photon in $MeV$ is: