Anna University Chennai B.Tech Ph 2161 engineering physics-ii 2010 Question paper

B.E/B.TECH DEGREE EXAMINATION,JUNE 2010
SECOND SEMESTER
PH 2161-ENGINEERING PHYSICS-II
(REGULATION 2008)

PART A( 10X2=20 MARKS )

1. Mention the demerits of classical free electron theory.

2. Calculate the Fermi energy of copper at 0k if the concentration of electron is 8.5x 10^28m^-3.

3. Distinguish between n-type and p-type.

4. Mention the uses of Hall Effect.

5. The transition temperature for superconducting material is 3.7 k at zero magnetic field and critical field is 0.0306 A/m at 0k.calculate the critical field at 2k.

6. Define anti ferromagnetism. Mention two materials that exhibit anti ferromagnetism.

7. What is ionic polarization? Write an expression for ionic Polarisability.

8. State the properties of ferroelectric materials.

9. Explain shape memory effect.

10. Name the types of metallic glasses and mention few metallic glasses.

PART B-(5 X 16=80)

11.
i. Define drift velocity and relaxation time.
ii. Derive an expression for both electrical conductivity and thermal conductivity of electrons in metal.

Or

12
i. Define density of states.
ii. Derive an expression for the density of states in a metal.
iii. A conducting rod contains 8.5 x 10^28 electrons per cubic meter. Calculate the electrical conductivity and mobility of electrons, if the collision time for scattering is 2 x 10^-14 sec.

13.
i. Derive an expression for the concentration of electrons in the conduction band of an intrinsic semiconductor.

ii. With necessary theory, describe the method of determining the band gap of an intrinsic semiconductor.

Or

14.
i. What is Hall Effect?
ii. Give the theory of Hall Effect.
iii. The density of silver is 10.5 x 10^3 kg/m^3.the atomic weight of silver is 107.9. assume that each silver atom provides one conduction electron. the electrical conductivity of silver at 20c us 6.8 x 10^7 ohm^-1m^-1.determine the carrier concentration and mobility of electrons, if N=6.02 x 10^26 atom/k. mol.

15.
i. Give the Weiss theory of ferromagnetism and derive an expression for its susceptibility.

ii. Describe the structure, properties and applications of ferrites.

Or

16.
i. Distinguish between soft and hard magnetic materials.

ii. Explain meissner effect.

iii. Describe type I and type ii superconductors.

17.
i. Define local field in a dielectric.
ii. Derive an expression for the local field in a dielectric for a cubic structure.
iii. Deduce clarsirs-mosatti relation.

Or

18.
i. Discuss in detail the different dielectric breakdown mechanisms.
ii. Describe the frequency dependence of polarization of a dielectric material.

19.
i. What are metallic glasses? how are they prepared?
ii. Describe their properties and application.

Or

20.
i. What are nano-phase materials?
ii. Describe the method of producing nano materials using
a.Chemical vapour deposition method
b.Plasma assisted deposition method.

iii. Write a short note on carbon nano tubes.