Energy in the sun is generated mainly by

Fission of nuclei is possible because the binding energy per nucleon in them

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

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

In the nuclear fusion reaction $_1^2H + _1^3H \to _2^4He + n$,the repulsive potential energy between the two nuclei is $7.7 \times 10^{-14} \, J$. To what temperature must the gas be heated to initiate the reaction? $[k = 1.38 \times 10^{-23} \, J/K]$

The phenomenon in which a proton flips is