The power obtained in a reactor using $\mathrm{U}^{235}$ disintegration is $1000 \mathrm{~kW}$. The mass decay of $\mathrm{U}^{235}$ per hour is

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Aicharya · Accepted Answer

Let assume power $P=1000 \mathrm{~W}$
Energy per hour $=1000 \times 3600 \mathrm{~J}$
Energy per fission $=200 \mathrm{MeV}$
$=200 \times 1.6 \times 10^{-13} \mathrm{~J}$
$\therefore$ Number of fission per hour
$n=\frac{1000 \times 3600}{200 \times 1.6 \times 10^{-13}}$
$\begin{aligned}
& \text {Number of mole per hour }=\frac{n}{N} \\
& \therefore \text { Mass per hour }=\frac{n}{N} \times 235
\end{aligned}$
$\begin{aligned}
& =\frac{1000 \times 3600 \times 235}{200 \times 1.6 \times 10^{-13} \times 6.02 \times 10^{23}} \\
& =43.9 \times 10^{-6} \mathrm{~g}
\end{aligned}$
This $43.9 \times 10^{-6} \mathrm{~g}$ is nearest value of 40 micro gram so option (b) is correct.

The power obtained in a reactor using $\mathrm{U}^{235}$ disintegration is $1000 \mathrm{~kW}$. The mass…

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