The binding energy per nucleon of ${ }_{8}^{16}O$ is $7.97 \text{ MeV}$ and that of ${ }_{8}^{17}O$ is $7.75 \text{ MeV}$. The energy required to remove one neutron from ${ }_{8}^{17}O$ is $\qquad \text{ MeV}$.

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A:$ The binding energy per nucleon is practically independent of the atomic number for nuclei of mass number in the range $30$ to $170$.
Reason $R:$ Nuclear force is short-ranged.
In the light of the above statements, choose the correct answer from the options given below:

The mass defect in a particular nuclear reaction is $0.3 \,g$. The amount of energy liberated in kilowatt-hour $(kWh)$ is: (Velocity of light $c = 3 \times 10^8 \,m/s$)

The binding energy of a nucleus is equivalent to

Energy of $1 \, g$ uranium is equal to

$A$ nucleus of mass $ 20 u $ emits a $ \gamma $ photon of energy $ 6 MeV $. If the emission is assumed to occur when the nucleus is free and at rest, then the nucleus will have a kinetic energy nearest to (take $ 1 u = 1.6 \times 10^{-27} kg $): (in $keV$)