B.E./B.Tech. DEGREE EXAMINATION, NOVEMBERIDECEMBER 2009
Second Semester
Civil Engineering
PH 2161 - ENGINEERING PHYSICS - II
(Regulation 2008)
(Common to all branches)
Time: Three hours Maximum: 100 Marks
Answer ALL Questions
PART A - (10 x 2 =20 Marks)
1. Find the drift velocity of the copper wire whose cross sectional area is 1 mm when the wire carries a current of 10 A. Assume that each copper atom contributes one electron to the electron gas. Given n =8.5 x 1028 m".
2. State Wiedemann-Franz Law.
3. Define Hall effect and Hall voltage.
4. What is the difference between n-type and p-type semiconductor?
5. What do you mean by energy product?
6. What is domain theory offerromagnetism?
7. Define ionic and orientation polarization.
8. What is discharge breakdown?
9. What are shape memory alloys? Give examples.
10. Explain the importance of mechanical properties of nano phase materials.
PART B - (5 x 16 = 80 Marks)
11. (a) (i) Explain Fermi-Dirac distribution function and how it varies with temperature. (8)
(ii) Derive an expression for the density of states and based on that calculate the carrier concentration in metals. (8)
Or
(b) Discuss classical free electron theory of metals. Obtain the expression for electric resistivity in terms of well known microscopic quantities. Discuss its dependence on temperature. (16)
12. (a) Obtain an expression for density of electrons in the conduction band of an n-type and density of holes in the valence band of an p-type intrinsic semiconductor. (16)
Or
(b) (i) Explain Hall effect in p-type and n-type semiconductors. (6)
(ii) Derive an expression of Hall coefficient. (4)
(iii) Describe the experimental setup for the measurement of Hall coefficient. (6)
13. (a) (i) Explain hysteresis on the basis of domain theory of ferromagnetism. (8)
(ii) Distinguish between soft and hard magnetic materials. (8)
Or
(b) (i) Explain in detail high Tc , superconductors with examples. (6)
(ii) Write a note on isotope effect. Describe type I and type II superconductors with suitable diagrams. (10)
14. (a) (i) Briefly explain the effects of frequency and temperature on polarization of dielectrics. (10)
(ii) Deduce the Clausius-Mosotti relation. (6)
Or
(b) (i) Explain ferroelectric materials and their properties. (10)
(ii) Write any five applications of ferroelectric materials. (6)
15. (a) (i) Discuss the applications of nanomaterials in various fields. (6)
(ii) Discuss any two techniques of synthesis of carbon nanotubes and mention its properties. (10)
Or
(b) Give a detailed account on metallic glasses, their method of production, types, properties and applications. (16)