Master of Science II (Physics-Material Science)
Examination: Oct Nov 2016 Semester IV (New CGPA)
SLR No. Day
Date Time Subject Name Paper No. Seat No.
SLR SH
562
Tuesday
22/11/2016
02.30 PM
To
05.00 PM
Magnetic Materials
C
XV
Instructions: Q. no. 1 and Q. no 2 are compulsory
Attempt any three questions from Q. No.3 to Q. No. 7
All questions carry equal marks.
Use of non programmable calculator is allowed
Total Marks: 70
Q.1 Choose correct alternative 08
Unit of magnetic flux density is
Wb/m2 Wb/A.m
A/m Tesla/m
Example of dia-magnetic materials is
Super conductor Alkali metals
Transitions metals ferrites
Ferrites susceptibility of ferro-magnetic material is

105 10-5 to 10-2
Typical thickness of Bloch walls is
0.1-1 1-10
10-50 100
Example of soft magnet is
45 permalloy CrO2
Fe-Pd Alnico
Example of magnetic material used in data storage devices is
45 permalloy CrO2
Cunife Alnico
Hysteresis is a phenomenon of in a magnetic circuit
Setting up constant flux Lagging of H behind B
Lagging B behind H Leading B ahead H
If the magnetic material is located within a coil through which alternating current
(60 Hz frequency) flows, then hysteresis loops will be formed every
second
60 120
30 180
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State True of False 06
Q.2 Write short notes on: 14
Vibrating Reed magnetometer
Antiferromagnetic Alloys

05
05
04
Q.3 Discuss in detail the classical theory of paramagnetism.
What is gyro magnetic effect?
08
06
Q.4 Give a brief account of weiss molecular Field Theory of Ferromagnetism
Write a note on exchange forces in ferromagnetic materials.
10
04
Q.5 What is diffraction? Explain in brief the neutron diffraction.
Explain the structure of cubic ferrites.
08
06
Q.6 Explain molecular field theory of ferromagnetic materials.
Explain anisotropy in hexagonal crystals.
08
06
Q.7 Explain magnetostriction of single crystals.
Explain the shape hysteresis loop of a magnetic materials.
08
06
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