Electrical and Electronics Engg. Materials

ELECTRICAL & ELECTRONICS ENGINEERING MATERIALS
SEM-IV, 2013
B.TECH EXAMINATION
UTTARAKHAND TECHNICAL UNIVERSITY
(UTU)

Time: 2 hrs

Total marks: 50

Note: Attempt all questions.

Q1:- Attempt any four:

1. State and explain Bragg's law?
2. What do you understand by structural Imperfections
3. How the bonds in solids are formed? Explain.
4. Explain how materials can be classified into three groups on the basis of atomic structure?
5. Explain the factors which change the resistivity of a conducting material?
6. What is polarization? Explain.

Q2:- Attempt any two:

1. Explain the following.
   (a) Permeability
   (b) Dielectric constant
2. Explain ferroelectricity and piezoelectricity.
3. Explain the terms dielectric constant and dielectric loss.

Q3:- Attempt any two:

1. Write a note on superconductors.
2. Classify the conducting materials. Describe their properties.
3. What is effect of temperature on conductivity of semiconductor?

Q4:- Attempt any two:

1. Draw the hysteresis loop for a soft magnetic material and compare it with the hysteresis loop of hard magnetic material. Give two examples of each.
2. Give a short description of soft ferrites.
3. Explain:
   (a) Eddy currents.
   (b) Magnetostriction.

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