21. If the wavelength of the first line of the Balmer series in the hydrogen spectrum is $$\lambda $$, then the wavelength of the first line of the Lyman series is
22. For a diatomic molecule with the vibrational quantum number n and rotational quantum number J, the vibrational level spacing ΔEn = En - En - 1 and the rotational level spacing ΔEJ - EJ - EJ - 1 are approximately
23. If R1 is the value of the Rydberg constant assuming mass of the nucleus to be infinitely large compared to that of an electron, and if R2 is the Rydberg constant taking nuclear mass to be 7500 times the mass of the electron, then the ratio $$\frac{{{R_2}}}{{{R_1}}}$$ is
24. Three values of rotational energies of molecules are given below in different units
P = 10 cm-1
Q = 10-23 J
R = 104 MHz
Choose the correct arrangement in the increasing order of energy.
P = 10 cm-1
Q = 10-23 J
R = 104 MHz
Choose the correct arrangement in the increasing order of energy.
25. The coherence length of laser light is
26. The spectral terms for a certain electronic configuration are given by 3d, 1d, 3p, 1p, 5s, 3s. The term with the lowest energy is
27. In accordance with the selection rules of electric dipole transitions, the 43p1 state of helium can decay by photon emission to the states
28. Light of wavelength 1.5 μm incident on a material with a characteristic Raman frequency of 20 × 1012 Hz results in a Stokes-shifted line of wavelength
[Given : c = 3 × 108 m/s]
[Given : c = 3 × 108 m/s]