Hydrogen atom in ground state is excited by a monochromatic radiation of λ = 975 Å. Number of spectral lines…

2 2014 AIPMT AtomsHydrogen spectrum Medium
Hydrogen atom in ground state is excited by a monochromatic radiation of $\lambda$ = 975 Å. Number of spectral lines in the resulting spectrum emitted will be
A 3
B 2
C 6
D 10

Detailed Solution

Energy of the photon: $E = \frac{12400}{975}$ eV ≈ 12.75 eV
Energy of the excited state $= -13.6 + 12.75 = -0.85$ eV, which is the n = 4 level.
Number of spectral lines from n = 4: $\frac{n(n-1)}{2} = \frac{4\times3}{2} = 6$

Hydrogen spectrum in past papers

7 questions from this chapter have appeared across 5 exam years.

Keep going

Practise Hydrogen spectrum All 7 questions This chapter in 2014 AIPMT