Q 12-12-101JEE MainJEE Main 2021 (27 Aug, Shift 2)Easy
$X$ different wavelength may be observed in the spectrum from a hydrogen sample if the atoms are excited to states with principal quantum number $n = 6$? The value of $X$ is
Numerical value type. Enter your answer.
Answer: 15
Number of possible spectral lines from level $n$:
$$X = \frac{n(n - 1)}{2} = \frac{6\times5}{2} = 15$$
Solution by Sreeraj P, M.Sc Physics