The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about $9$. The spectral series are:

A $50$ watt bulb emits monochromatic red light of wavelength of $795 \mathrm{nm}$. The number of photons emitted per second by the bulb is $x\times {10}^{20}.$ The value of $x$ is _____ .

(Nearest integer)

$\text{ [Given : }\left.\mathrm{h}=6.63\times {10}^{-34}\mathrm{Js}\text{ and} \mathrm{c}=3.0\times {10}^8 {\mathrm{ms}}^{-1}\right]$

Consider the following pairs of electrons:

(A) (a) $\mathrm{n}=3, \mathrm{l}=1, {\mathrm{m}}_{\mathrm{l}}=1,{\mathrm{m}}_{\mathrm{s}}=+\frac{1}{2}$
(b) $\mathrm{n}=3, \mathrm{l}=2,{\mathrm{m}}_{\mathrm{l}}=1,{\mathrm{m}}_{\mathrm{s}}=+\frac{1}{2}$
(B) (a) $\mathrm{n}=3, \mathrm{l}=2,{\mathrm{m}}_{\mathrm{l}}=-2,{\mathrm{m}}_{\mathrm{s}}=-\frac{1}{2}$
(b) $\mathrm{n}=3, \mathrm{l}=2,{\mathrm{m}}_{\mathrm{l}}=-1,{\mathrm{m}}_{\mathrm{s}}=-\frac{1}{2}$
(C) (a) $\mathrm{n}=4, \mathrm{l}=2,{\mathrm{m}}_{\mathrm{l}}=2,{\mathrm{m}}_{\mathrm{s}}=+\frac{1}{2}$
(b) $\mathrm{n}=3,\mathrm{l}=2,{\mathrm{m}}_{\mathrm{l}}=2,{\mathrm{m}}_{\mathrm{s}}=+\frac{1}{2}$

The pairs of electrons present in degenerate orbitals is/are: