Atomic and Molecular Physics - Physics Previous Year Questions

1

2007 · Physics · Atomic and Molecular Physics · Atomic Spectra and Coupling

Physics (PH) 2007

If an atom is in the \( ^3D_2 \) state, the angle between its orbital and spin angular momentum vectors (\( \vec{L} \) and \( \vec{S} \)) is

A

\(\cos^{-1} \frac{1}{\sqrt{3}} \)

B

\(\cos^{-1} \frac{2}{\sqrt{3}} \)

C

\(\cos^{-1} \frac{1}{2} \)

D

\(\cos^{-1} \frac{\sqrt{3}}{2} \)

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2

2008 · Physics · Atomic and Molecular Physics · Molecular Spectra

Physics (PH) 2008

A pure rotational Raman spectrum of a linear diatomic molecule is recorded using electromagnetic radiation of frequency \(\nu_e\). The frequency of two consecutive Stokes lines are

A

\(\nu_e - 10B, \quad \nu_e - 14B\)

B

\(\nu_e - 2B, \quad \nu_e - 4B\)

C

\(\nu_e + 10B, \quad \nu_e + 14B\)

D

\(\nu_e + 2B, \quad \nu_e + 4B\)

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3

2013 · Physics · Atomic and Molecular Physics · Atomic Spectra and Coupling

Physics (PH) 2013

The number of spectral lines allowed in the spectrum for the 3 ^2D → 3 ^2P transition in sodium is __________.

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4

2014 · Physics · Atomic and Molecular Physics · Atomic Spectra and Coupling

Physics (PH) 2014

The emission wavelength for the transition \(^1D_2 \rightarrow ^3F_3\) is 3122 Å. The ratio of populations of the final to the initial states at a temperature 5000 K is (h = 6.626 × 10⁻³⁴ J.s, c = 3 × 10⁸ m/s, k_B = 1.380 × 10⁻²³ J/K)

A

2.03 × 10⁻⁵

B

4.02 × 10⁻⁵

C

7.02 × 10⁻⁵

D

9.83 × 10⁻⁵

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5

2024 · Physics · Atomic and Molecular Physics · Atomic Spectra and Coupling

Physics (PH) 2024

An atom is subjected to a weak uniform magnetic field \(\vec{B}\). The number of lines in its Zeeman spectrum for transition from \(n = 2, l = 1\) to \(n = 1, l = 0\) is

A

8

B

10

C

12

D

5

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6

2007 · Physics · Atomic and Molecular Physics · Molecular Spectra

Physics (PH) 2007

The solid phase of an element follows van der Waals bonding with inter-atomic potential \( V(r) = -\frac{P}{r^6} + \frac{Q}{r^{12}} \), where \( P \) and \( Q \) are constants. The bond length can be expressed as

A

\(\left(\frac{2Q}{P}\right)^{-6} \)

B

\(\left(\frac{Q}{P}\right)^{-6} \)

C

\(\left(\frac{P}{2Q}\right)^{-6} \)

D

\(\left(\frac{P}{Q}\right)^{-6} \)

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