Jawaharlal Nehru Technological University Anantapur 2009 B.Tech Regular s,e ENGINEERING PHYSIC set - 2 - Question Paper
Code No: 09A1BS02 R09 Set No. 2
I B.Tech Regular Examinations,June 2010 ENGINEERING PHYSICS Common to CE, ME, CHEM, BME, IT, MECT, MEP, AE, BT, AME, ICE, E.COMP.E, MMT, ETM, EIE, CSE, ECE, EEE Time: 3 hours Max Marks: 75
Answer any FIVE Questions All Questions carry equal marks
What is statistical mechanics? Write notes on Bose-Einstein statistics.
1.
Write notes on black body radiation.
Calculate the energies that can be possessed by a particle of mass
c
8.50 x 10-31kg which is placed in an infinite potential box of width 10-9cm.
Code No: 09A1BS02 R09 Set No. 2
[6+5+4]
What is the meaning of nanotechnology? Explain.
2.
Describe the processes of sol-gel and precipitation in the fabrication of nano- structures.
Code No: 09A1BS02 R09 Set No. 2
Write the applications of nanotechnology in Electronic Industry. [4+7+4]
c
Write notes on volume defects in crystals.
3.
What is Burgers vector? What is Burgers circuit? Explain.
Code No: 09A1BS02 R09 Set No. 2
If the average energy required to create a Frenkel defect in an ionic crystal is
c
1.35 eV, calculate the ratio of Frenkel defects at 250C and 3500C. [5+6+4]
Discuss the band theory of solids and explain the formation of bands and concept of holes.
4.
a
b
What is effective mass of an electron? Derive an expression for the effective mass of an electron. [9+6]
Explain the formation and properties of an ionic crystal, with a suitable example.
5.
a
b
Derive an expression for the cohesive energy of an ionic crystal. [7+8]
a) What is Meissner effect? Explain, in detail.
6.
b) Distinguish a super-conductor and a normal metal, both maintained at same temperature.
Write notes on magnetic levitation. [5+5+5]
a) Explain the characteristics of a laser beam.
b) Describe the construction of He-Ne laser and discuss with relevant ELD, the working of He-Ne laser.
(c) What are the differences between a laser diode and an LED? [4+7+4]
8. (a) Derive an expression for carrier concentration of p-type semiconductors.
(b) Explain Hall effect and its importance.
(c) For a semiconductor, the Hall coefficient is -6.85 x 10-5 m3/coulomb, and electrical conductivity is 250 m-1 Q-1. Calculate the density and mobility of the charge carriers. [7+4+4]
2
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Earning: Approval pending. |