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 5 W is

$1.56 \times 10^{+10} s^{-1}$ $1.56 \times 10^{+11} s^{-1}$ $1.56 \times 10^{+16} s^{-1}$ $1.56 \times 10^{+17} s^{-1}$

$1.56 \times 10^{+11} s^{-1}$

$\frac{\text { Energy }}{\text { Fission }}=200 \mathrm{MeV}=200 \times 10^6 \times 1.6 \times 10^{-19}$ J Fission rate $=\frac{5}{200 \mathrm{MeV}}=1.56 \times 10^{11}$ fission/sec