51.
Match the typical spectra of stable molecules with the corresponding wave number range
P. Electronic spectra 1. 106 cm-1 and above
Q. Rotational spectra 2. 105 - 106 cm-1
R. Molecular dissociation 3. 100 - 102 cm-1

52.
The molecular spectra of two linear molecules O-C-O and O-C-S are recorded in the microwave region. Which one of the following statements is correct?

53.
If the equation of state for a gas with internal energy U is pV = $$\frac{1}{3}$$U, then the equation for an adiabatic process is

54.
The Lβ line of X-rays emitted from an atom with principal quantum numbers n = 1, 2, 3, . . . . . . . ., arises from the transition

55.
Five energy levels of a system including the ground state are shown below. Their lifetimes and the allowed electric dipole transitions are also marked.
Atomic and Molecular Physics mcq question image
Which one of the following transitions is the most suitable for a Continuous Wave (CW) laser?

56.
When the refractive index $$\mu $$ of the active medium changes by $${\Delta \mu }$$  in a laser resonator of length L, the change in the spectral spacing between the longitudinal modes of the laser is (c is the speed of light in free space)

58.
For an electron in hydrogen atom, the states are characterized by the usual quantum numbers n, $$l$$, m$$l$$. The electric dipole transition between any two states requires that

59.
Match the following:
P. Franck-Hertz experiment 1. Electronic excitation of molecules
Q. Hartree-Fock method 2. Wave function of atoms
R. Stern-Gerlach experiment 3. Spin angular momentum of atoms
S. Franck-Condon principle 4. Energy levels in atoms

60.
X-rays were produced using cobalt (Z = 27) as target. It was observed that the X-ray spectrum contained a strong Kα line of wavelength 0.1785 nm an a weak Kα line of wavelength 0.1930 nm. Then the weak Kα line is due to an impurity whose atomic number is