In nuclear fission,the percentage of mass converted into energy is about: (in $\%$)

Two lithium nuclei in a lithium vapour at room temperature do not combine to form a carbon nucleus because

In a reactor, $2 \, kg$ of ${ }_{92} U ^{235}$ fuel is fully used up in $30$ days. The energy released per fission is $200 \, MeV$. Given that the Avogadro number, $N_A = 6.023 \times 10^{26} \, \text{per kilo mole}$ and $1 \, eV = 1.6 \times 10^{-19} \, J$. The power output of the reactor is close to $..... \, MW$.

In a nuclear reactor,the fuel is consumed at the rate of $1 \times 10^{-3} \text{ g s}^{-1}$. The power generated in kW is

In a nuclear fission reaction:

Assertion: Heavy water is a better moderator than normal water.
Reason: Heavy water absorbs neutrons more efficiently than normal water.