I B.Tech - Regular Examinations, June 2009
First Year
APPLIED PHYSICS - SET NO: 2
(Regulation 2007)
Time : 3 hours |
Maximam Marks:80 |
Answer any FIVE Questions
1. (a) Explain the terms
i. basis
ii. space lattice
iii. lattice parameters and
iv. unit cell.
(b) Describe the seven crystal systems with diagrams.
2.(a) Explain the properties of matter waves.
(b) Describe GP Thomson’s experiment to verify the wave nature of matter.
3.(a) What are the salient features of Sommerfeld theory of metals? Explain.
(b) Explain the Fermi-Dirac distribution function of electrons.
(c) Use the Fermi distribution function to obtain the value of F(E) for E - EF =
0.01 eV at 200 K.
4. (a) Explain the terms:
i. magnetic induction
ii. magnetic susceptibility
iii. permeability of a medium and
iv. intensity of magnetization.
(b) Explain the origin of magnetic moment. Find the magnetic dipole moments
due to orbital and spin motions of an electron.
(c) A magnetic material has a magnetization of 3300 amp/m, and flux density of
0.0044 weber/sq.m. Calculate the magnetizing force and the relative perme-
ability of the material. [permeability of vacuum = 4p × 10-7 H/m] [6+6+4]
5. (a) Write a note on Meissner effect relating to superconductivity.
(b) Compare the differences between soft and hard superconductors.
(c) Calculate the critical current that flow through a long thin superconducting
wire of aluminium of diameter 10-3 m. (Given critical magnetic field = 7.9 ×
103A/m).
6. (a) Explain the need of a cavity resonator in a laser.
(b) With the help of a suitable diagram describe the construction and working of
a semiconductor laser.
(c) Write any four applications of laser.
7.(a) Explain the transmission of a signal through the step-index fiber.
(b) Discuss different losses in optical fibers.
(c) An optical fiber has a core material of refractive index of 1.55 and cladding ma-
terial of refractive index 1.50. The light is launched into it from air. Calculate
its numerical aperture.
8. (a) What are nanomaterials? Explain.
(b) Describe the various types of carbon nanotubes.
(c) Explain the fabrication of carbon nanotubes.
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