CLASS: M.Sc. PHYSICS
14A/ 418
St. JOSEPH’S COLLEGE (AUTONOMOUS) TIRUCHIRAPPALLI – 620 002
SEMESTER EXAMINATIONS – APRIL 2014
TIME: 3 Hrs.
MAXIMUM MARKS: 100
SEM
SET
PAPER CODE
TITLE OF THE PAPER
IV
2012
12PPH4113
CONDENSED MATTER PHYSICS
SECTION – A
Answer all the questions:
20 x 1 = 20
Choose the correct answer:
1. The efficiency of simple Hexagonal lattice is
a) 60%
b) 70%
c) 80%
d) 90%
2. The phenomenon of the Kirkendall effect is due to
a) High diffusion
b) Low diffusion in binary alloy
c) Equal diffusion in binary alloy
d) Unequal diffusion in binary alloy
3. The value of Lorentz number is
a) 2.54  10-8 watt ohm deg-2
c) 2.45  10-8 watt ohm deg-2
b) 5.25  10-10 watt ohm
d) 4.52  10-10 watt deg-2
4. The Langevin – Debye equation is given by
p2
a) L = L 0 
3KT
a2
c) L = L 0 
3KT
L
L = p0  0
b)
3KT
p2
d) L = L 0 
3KT
5. Bohr magneton is given by the equation
 eh
B =
 =
a)
b) B
4m
e2h
c) B =
d) B =
4m
eh
4m
eh 2
4m
Fill in the blanks:
6.
The condition for-in-phase scattering by a set of equidistant
parallel planes in a crystal is given by ______.
7.
A slight variation in interstitial diffusion mechanism is
called ______.
8.
Wiedemann and Franz observed that the ratio ______ remains
constant for all the metals at a fixed temperature.
9. The Fermi-Dirac distribution function is given by ______.
10. The exchange energy (Eex) is minimum when the spins are aligned
in ______ fashion.
State True or False:
11. The concept of reciprocal lattice plays a very important role in the
field of x-ray crystallography.
12. The phenomenon of unequal diffusion in binary alloy was first
observed by Kirkendall.
13. The volume of the Fermi surface represents the number of
conduction protons.
14. Fermi-Dirac distribution function is given by
1
F(E) =
 E  EF 
exp
 1
KT


15. Ferromagnetic materials are made up of large number of domains.
Each domain contains about 109 – 1015 atoms.
Answer in one or two sentences:
16. In how many ways close packed structures can be classified?
17. What is meant by dissociative diffusion?
18. What is LCAO?
19. Write the Clausius – mosotti equation.
20. Give Curie-Weiss law.
SECTION – B
Answer all the questions:
5 x 6 = 30
21. a. Explain the close packing of equal spheres in 3-dimensions.
OR
b. Interpret the Bragg’s equation with necessary diagrams.
22. a. Deduce an expression for Fick’s second law of diffusion.
OR
b. Explain briefly about the Kirkendall effect.
23. a. Give the characteristics of Fermi surfaces.
OR
b. Explain the necessary equations about the Meissner effect.
24. a. Discuss about the Hall effect in Semiconductors.
OR
b. Derive an expression for the classical theory of Electronic
Polarizability.
25. a. Obtain an expression for the Langevin’s classical theory of
paramagnetism.
OR
b. Write a note on “Ferrimagnetism and Ferrites”.
SECTION – C
Answer any FOUR questions:
4 x 12.5 = 50
26. Explain the X-ray diffraction experiment and give an account of
powder method of crystal structure analysis.
27. Derive an expression for the specific heat of solids on the basis of
Debye model at low temperature.
28. What do you mean by normal Tunneling? Also explain Josephson
effect with necessary diagrams.
29. What is Ferroelectricity? Prove that the dielectric constant follows
Curie-Weiss law.
30. Describe the Langevin’s classical theory of diamagnetism.
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