QP Code
1
6
0
0
5
0
Register Number
VELALAR COLLEGE OF ENGINEERING AND TECHNOLOGY
(An Autonomous Institution, Affiliated to Anna University, Chennai)
Semester Examinations Apr May 2017
Regulations-2016
Programme:
B.E/B.Tech
Semester:
2
Max. Marks:
100
Duration
3 Hrs
Course Code Title:
16PHT21
MATERIALS SCIENCE
Knowledge Levels
K1 Remembering
K3 Applying
K5 Evaluating
K2 Understanding
K4 Analysing
K6 Creating
Part A Answer ALL Questions. 10 x 2 20 Marks
No.
Question
KL
1.
State Wiedemann-Franz law.
K1
2.
Copper at 300 K has an electrical conductivity of 6.4 x 107 ohm-1m-1. Calculate the thermal conductivity of copper. Lorentz number is L=2.45 x 10-8 W.ohm.K-2
K3
3.
Recall intrinsic semiconductor.
K2
4.
What is meant by direct bandgap semiconductor?
K1
5.
Define Bohr magneton.
K1
6.
What is meant by transition temperature of superconductor?
K2
7.
Define dielectric constant.
K2
8.
Infer ferroelectricity.
K2
9.
What is nitinol?
K1
10.
Why the properties of materials are changed at nano scale?
K4
Part B Answer ALL Questions. 5 x 16 80 Marks
No
Question
Marks
KL
11.
a
Deduce the mathematical expressions for electrical conductivity and thermal conductivity of a material.
16
K2
OR
b
i.
Write and explain Fermi Dirac distribution function. Explain with the help of a diagram how Fermi function varies with temperature.
8
K2
ii.
Derive the expression for carrier concentration in a metal.
8
K2
12.
a
i.
Obtain the expression for Fermi level in an intrinsic semiconductor and also explain the variation of Fermi level with temperature.
10
K2
ii.
Explain band gap determination of a semiconductor.
6
K2
OR
b
i.
Derive the expressions for carrier concentration and Fermi energy in an N-Type Semi conductor.
12
K2
ii.
Show the variation of Fermi level with temperature and impurity concentration of N-Type Semi conductor.
4
K3
13.
a
i.
Explain the classification of magnetic materials with their properties in detail.
8
K4
ii.
What are soft and hard magnetic materials? Distinguish between soft and hard magnetic materials.
8
K4
OR
b
i.
Explain the various properties of super conducting materials.
10
K2
ii.
Discuss type-I and type-II super conductors in details.
6
K2
14.
a
i.
Explain electronic, ionic, orientational and space charge polarization in detail.
10
K4
ii.
Discuss in detail frequency and temperature dependence of polarization.
6
K4
OR
b
i.
Derive an expression for internal field in a dielectric material.
12
K2
ii.
Deduce Clausius Mosotti relation.
4
K3
15.
a
i.
What are metallic glasses? State their types.
4
K2
ii.
Discuss the preparation, properties and applications of metallic glasses.
12
K2
OR
b
i.
Explain pulsed laser deposition and chemical vapour deposition methods for the preparation of nanomaterials.
10
K2
ii.
Explain birefringence and also explain Kerr optical effect.
6
K2