Anna University Chennai Anna University - Trichy, B.E/B.Tech DEGREE EXAMINATION, JUNE 2010. PHYSICS - II Question paper

B.E./B.Tech. DEGREE EXAMINATION, JUNE 2010

SECOND SEMESTER

HS1152 ENGINEERING PHYSICS - II

(Common to All Branches)

(REGULATION 2008)

Time: Three hours Maximum: 100 marks

Answer ALL questions.

PART A - (10 x 2 = 20 marks)

1. Define Density of energy states

2. What is Fermi energy level?

3. The instrinsic carrier density of a semiconductor is 2.1 x 10^19 m^-3. The electron and hole mobilities are 0.4 and 0.2 m^2/volt-s respectively. Calculate the conductivity.

4. Define Hall coefficient.

5. What are Cooper pairs?

6. Distinguish between Hard and Soft Magnetic materials.

7. What is meant by dielectric breakdown?

8. Define dielectric constant.

9. Mention few applications of metallic glasses.

10. Name any four properties of carbon nanotubes.

PART A - (5 x 16 = 20 marks)

11. Write Fermi-dirac distribution function. Explain how Fermi function varies with temperature. Evaluate the Fermi function for energy KT above the fermi energy. (2+10+4)

Or

12. What are the drawbacks of classical free electron theory? Derive an expression for density of energy state. (4+12)

13. Derive the expression for the carrier concentration of hole in an instrinsic semiconductor and hence deduce how Fermi energy level varies with temperature. (12+4)

Or

14. Explain with a neat sketch, the variation of Fermi level with temperature and impurity concentration in the case of n and p type semiconductors. What is Hall Effect? Give any four applications. (10+2+4)

15. What are ferrites? Describe the different types of ferrites structure with suitable diagram. What are the applications of ferrites? (2+10+4)

Or

16. (a) Define superconductivity. What are high temperature super conductors? Give four examples.
(2+6)
(b) Explain in detail about any four applications of super conductors. (8)

17. Derive an expression foe local field in a dielectric material. deduce Clausius Mosotti equation.
(10+6)
Or

18. Explain the different types pf polarization mechanisms involved in dielectric materials. (16)

19. What are shape memory alloys? Discuss their characteristics. List out any four applications.
(2+10+4)
Or

20. What are nanophase materials? Explain any two methods employed to produce nanophase materials. Mention any four applications. (2+12+2)