Cochin University of Science and Techology (CUST) 2008 B.Tech Electrical and Electronics Engineering ELECTRICAL MATERIAL SCIENCE - Question Paper

ELECTRICAL MATERIAL SCIENCE (EEE APRIL 2008)

1a. elaborate the different kinds of conductor materials? provide an application of every with its properties
b. discuss the terms relaxation time, collision time and mean free path as applied to conduction phenomenon
c. discuss the zone refining purification process of semiconductor materials
2a. explain the properties and specifications of wire and cable materials
b. explain the major drawbacks of classical free electron theory. How these drawbacks are eliminated in quantum approach
c. discuss any 1 method employed for fabricating PN junction
3a. Differentiate the various mechanisms of polarization in dielectrics
b. Derive Clausiees-Mossotti relation in dielectrics
c. Compare ferroelectricity and ferromagnetism
4a. What is loss tangent? What is its significance?
b. Prove that absorption of energy is proportional to the imaginary part of the complex dielectric constant
c. Derive the relation ranging from polarisation P and external electric field E
5a. discuss the breakdown mechanisms in gases and liquids
b. explain the electrical, mechanical and thermal properties of insulating materials
6a. define how insulating materials are classified on the basis of temperature. provide examples of every
b. Mention properties and applications of the subsequent insulating materials
i) Glass ii) PVC iii) Asbestos iv) Teflon v) Bakelite
7a. explain Langevin's theory of paramagnetism and diamagnetism
b. Classify the magnetic materials on the basis of dipole moment and discuss their properties
8a. Distinguish ranging from hard and soft magnetic materials. List a few materials under every category and provide their applications
b. elaborate the factors affecting permeability and hysterisis loss
9a. Differentiate photo thermal and photo voltaic conversion process
b. List the important properties and aplications of superconductors
10a.Discuss the properties of fuse materials. How the rating of fuse is fixed?
b. What is a solar cell? List the important characteristic of solar cell

Earning:   Approval pending.