M.Sc. (Semester III) (CBCS) Examination Nov/Dec-2018
(Materials Science)
ATOMIC, MOLECULAR NUCLEAR PHYSICS
Time: 2½ Hours Max. Marks: 70
Instructions: Q. 1 is compulsory.
Figures to the right indicate full marks.
Use of non programmable calculator is allowed.
Q.1 Multiple choice questions: 14
Total angular momentum is given by
−
−
The spacing between vibrational energy levels in CO molecule is found to be
8.44 × 10−2 Given that reduced mass of CO is 1.14 × Planck's
constant is 6.626 × 10−34 and 1.6 × The force constant of the
bond in CO molecule is
1.87N m 1870N m
18.7N m 187N m
One electron in d orbit and the other is in f orbit, in case of − coupling, the
atom may be in a
Only DFG SPD
PDFGH SPDFGH
jj coupling is coupling.
Weak Less Weak
Strong None of these
Which of the following molecules does not exhibit a rotational spectrum?
HCl H2
CO HBr
The Two-line method, Source Modulation method and the Zeeman effect are
important in atomic absorption spectroscopy because they:
Correct for absorbance from molecular species
Correct for the background created by the flame
Allow for the measurement of a small signal against a large background
All of the above
The Scattering amplitude of n-p interaction is
None of these
The doublets observed in alkali spectra are due to interaction.
Orbit Orbit Spin Spin
Spin orbit All of these
The electric quadrupole moment is negative; shape of the nuclei is
Oblate Prolate
Spherical All of these
10) For electronic excitation of molecules which is preferred
Page 2 of 2
SLR-VN-386
Hartree Fock method Stern Gerlect experiment
Franck- Hertz experiment Franck- Condon principle
11) In the nuclear shell model the spin parity of N 15 is given by
12) Deuteron has parity.
Even Odd
Even and odd None of the these
13) The can explain magic numbers.
Liquid drop model Fermi gas model
Shell model All of these
14) The selection rule for a rotational transition is
Δ J ± 1 ±1,±2,±3 …
Δ J ±1,±2,±3 … ±1
Q.2 Answer the following (any four) 08
State intensity rule for Zeeman effect.
Write any two limitations of liquid drop model.
What are types of nuclear reactions?
Give selection rules for L-S and j-j coupling.
What are the similarities of n-n and p-p forces
Write notes on (Any two) 06
What is liquid drop model of the nucleus and write its two limitations?
Explain vector atom model for LS-coupling
What are the consequences for bond elasticity for diatomic molecule as a
non-rigid rotator?
Q.3 Answer the following(Any two) 08
Write a note on type of nuclear reactions.
Distinguish between spherical top and asymmetric top molecules.
Distinguish between normal and anomalous Zeeman effect.
Answer the following (Any one) 06
Obtain the expression for semi-empirical mass formula of liquid drop
model.
In HCl, J 1 ← 0 transition occurs at 20.68 cm−1. The molecule is to be
considered as rigid rotator. The wavelength of J 15 ← 14.
Q.4 Answer the following (Any two) 10
Derive an expression for Lande g factor for LS coupling.
What is Zeeman effect? Write note on intensity rules for Zeeman effect of
two valence electron system.
Give the schematic representation of interaction energies between pd
electrons in L-S coupling.
Answer the following (Any one) 04
Write short note on statistical theory of nuclear reactions.
What are the limitations of shell theory?
Q.5 Answer the following (Any two) 14
Explain proton proton scattering at low energies.
What is the Q-value of a nuclear reaction? Determine the Q-equation of a
nuclear reaction.
Obtain the expression for Diatomic molecule as a non-rigid rotator.