The atomic mass of $${ }_6 \mathrm{C}^{12}$$ is $$12.000000 \mathrm{~u}$$ and that of $${ }_6 \mathrm{C}^{13}$$ is $$13.003354 \mathrm{~u}$$. The required energy to remove a neutron from $${ }_6 \mathrm{C}^{13}$$, if mass of neutron is $$1.008665 \mathrm{~u}$$, will be :

The radius of third stationary orbit of electron for Bohr's atom is R. The radius of fourth stationary orbit will be:

Given below are two statements: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$

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