Match the following items in Column-$A$ with their corresponding principles in Column-$B$:

Column-$A$	Column-$B$
$A$. Rocket propulsion	$P$. Bernoulli's principle in fluid dynamics
$B$. Aeroplane	$Q$. Total internal reflection of light
$C$. Optical fibres	$R$. Newton's laws of motion
$D$. Fusion test reactor	$S$. Magnetic confinement of plasma
	$T$. Photoelectric effect

Suppose a ${ }_{88}^{226} Ra$ nucleus at rest and in the ground state undergoes $\alpha$-decay to a ${ }_{86}^{222} Rn$ nucleus in its excited state. The kinetic energy of the emitted $\alpha$ particle is found to be $4.44 \text{ MeV}$. The ${ }_{86}^{222} Rn$ nucleus then goes to its ground state by $\gamma$-decay. The energy of the emitted $\gamma$-photon is . . . . . . . $\text{keV}$.
[Given: atomic mass of ${ }_{88}^{226} Ra = 226.005 \text{ u}$,atomic mass of ${ }_{86}^{222} Rn = 222.000 \text{ u}$,atomic mass of $\alpha$ particle $= 4.000 \text{ u}$,$1 \text{ u} = 931 \text{ MeV}/c^2$]

Calculate the power output of a ${}_{92}^{235}U$ reactor, if it takes $30 \, \text{days}$ to consume $2 \, \text{kg}$ of fuel, and if each fission releases $185 \, \text{MeV}$ of usable energy. (Given: Avogadro's number $= 6 \times 10^{23} \, \text{mol}^{-1}$) .......... $\text{MW}$ (in $.3$)

In a fission reaction ${}_{92}^{236}U \to {}^{117}X + {}^{117}Y + n + n$,the binding energy per nucleon of $X$ and $Y$ is $8.5\,MeV$,whereas that of ${}^{236}U$ is $7.6\,MeV$. The total energy liberated will be about:

On fission,a $U^{235}$ nucleus releases $3 \times 10^{-11} \, J$ of energy. In a $1 \, GW$ nuclear reactor,$4.2 \%$ of this energy is converted to useful energy. The $U^{235}$ consumed (in grams) in half an hour is closest to (Avogadro number $N_A = 6.023 \times 10^{23}$)

State the principle of an atomic bomb and identify the nuclear process that occurs within it.