If $S$ is the surface area of a nucleus of mass number $A$, then

Among the fundamental forces, which one of the following is the strongest force?

The shortest wavelength in Balmer series of hydrogen atom spectrum is approximately equal to (use $R_H=1.097 \times 10^7 \mathrm{~m}^{-1}$ )

What will be the energy released in joule, in the process of fission by 1 mg of ${ }_{92}^{240} \mathrm{U}$. Assume energy release per fission is 200 MeV .

[use Avogadro's number as $6 \times 10^{23}$ and 1 eV $=1.6 \times 10^{-19} \mathrm{~J}$ ]