Engineering Physics · all questions

Atomic and Molecular Physics
practice.

Practice every MCQ with options. Use Show answers when you want the correct option and solution.

77

Questions

1/4

Page

Pick an option on a question to see the right answer and solution.

Q1

All vibrations producing a change in the electric dipole moment of a molecule yield

Select an option to see the answer and solution.

Q2

A piece of paraffin is placed in a uniform magnetic field H₀. The sample contains hydrogen nuclei of mass m_p, which interact only with external magnetic field. An additional oscillating magnetic field is applied to observe resonance absorption. If g₁ is the g-factor of the hydrogen nucleus, the frequency at which resonance absorption takes place, is given by

Select an option to see the answer and solution.

Q3

Consider the following statements about molecular spectra:
P. CH₄ does not give pure rotational Raman lines
Q. SF₆ could be studied by rotational Raman spectroscopy
R. N₂ shows infrared absorption spectrum
S. CH₃CH₃ shows vibrational Raman and infrared absorption lines
T. H₂O₂ shows pure rotational spectrum
Choose the right combination of correct statements.

Select an option to see the answer and solution.

Q4

The hyperfine structure of Na(3²P_3/2) with nuclear

l

= 3/2 has

Select an option to see the answer and solution.

Q5

The number of hyperfine components observed in the electronic transition

^{2} p_{\frac{1}{2}} \to^{2} s_{\frac{1}{2}}

of an atom with nuclear spin

\frac{1}{2}

is

Select an option to see the answer and solution.

Q6

The spectral term for the atom with 70% filled subshell and only s =

\frac{3}{2}

is

Select an option to see the answer and solution.

Q7

A system has energy level E₀, 2E₀, 3E₀, . . . . . , where the excited states are triply degenerated. Four non-interacting bosons are placed in this system. If the total energy of these bosons is 5E₀, the number of microstates is

Select an option to see the answer and solution.

Q8

The far infrared rotational absorption spectrum of a diatomic molecule shows equidistant lines with spacing 20 cm^-1. The position of the first stokes line in the rotational Raman spectrum of this molecule is

Select an option to see the answer and solution.

Q9

The three principal moments of inertia of a methanol (CH₃OH) molecule have the property

I_{x} = I_{y} = I

and

I_{z} \neq = I .

The rotational energy eigenvalues are

Select an option to see the answer and solution.

Q10

The total number of Zeeman components observed in an electronic transition

^{2} d_{\frac{5}{2}} \to^{2} p_{\frac{3}{2}}

of an atom in a weak field is

Select an option to see the answer and solution.

Q11

The number of fundamental vibrational modes of CO₂ molecule is

Select an option to see the answer and solution.

Q12

The spectrum of radiation emitted by a black body at a temperature 1000 K peaks in the

Select an option to see the answer and solution.

Q13

In a diatomic molecule, the inter-nuclear separation of the ground and first excited electronic state are the same as shown in the figure. If the molecule is initially in the lowest vibrational state of the ground state, then the absorption spectrum will appear as
Atomic and Molecular Physics mcq question image

Atomic and Molecular Physics mcq question image

Select an option to see the answer and solution.

Q14

The Lande g-factor for the

^{3} p_{1}

level of an atom is

Select an option to see the answer and solution.

Q15

A three-level system of atoms has N₁ atoms in level E₁, N₂ in level E₂ and N₃ in level E₃ (N₂ > N₁ > N₃ and E₁ < E₂ < E₃). Lasere mission is possible between the levels

Select an option to see the answer and solution.

Q16

The principal series of spectral lines of lithium is obtained by transitions between

Select an option to see the answer and solution.

Q17

An atom with one outer electron having orbital angular momentum

l

is placed in a weak magnetic field. The number of energy levels into which the higher total angular momentum state splits, is

Select an option to see the answer and solution.

Q18

In a He-Ne laser, the laser transition takes place in

Select an option to see the answer and solution.

Q19

Which one of the following electronic transitions in neon is not responsible for LASER action in a helium-neon laser?

Select an option to see the answer and solution.

Q20

The spin-orbit coupling constant for the upper state of sodium atom which emits D lines of wave numbers 16956.2 and 16973.4 cm^-1 is

Select an option to see the answer and solution.