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

To generate a power of $3.2 \text{ MW}$,the number of fissions of $^{235}\text{U}$ per minute is (Energy released per fission $= 200 \text{ MeV}$,$1 \text{ eV} = 1.6 \times 10^{-19} \text{ J}$)

The energy released in the fusion of $2 \ kg$ of hydrogen deep in the sun is $E_{H}$ and the energy released in the fission of $2 \ kg$ of ${ }^{235} U$ is $E_U$. The ratio $\frac{E_H}{E_U}$ is approximately :
(Consider the fusion reaction as $4{ }_1^1 H + 2 e^{-} \rightarrow { }_2^4 He + 2 \nu + 6 \gamma + 26.7 \ MeV$,energy released in the fission reaction of ${ }^{235} U$ is $200 \ MeV$ per fission nucleus and $N_{A} = 6.023 \times 10^{23}$ )

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:

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

Solar energy is mainly caused due to