JNTU Exam Papers I B.Tech Regular Examinations, May/Jun 2008 APPLIED PHYSICS

I Year  B.Tech Regular Examinations, May/Jun 2008



1. (a) What is Bragg’s law? Explain.
(b) Describe Laue’s method for the determination of crystal structure.
(c) The Bragg’s angle in the first order for (2 2 0) reflection from nickel (FCC) is 38.20 when X-rays of wavelength 1.54 °A are employed in a diffraction experiment. Determine the lattice parameter of nickel.
2. (a) Explain, in detail, the properties of matter waves.
(b) Describe Davisson and Germer experiment to verify the wave nature of matter.

3. (a) Distinguish between classical free electron theory and quantum free electron theory of metals.
(b) Explain the Fermi-Dirac distribution function of electrons. Explain the effect
of temperature on the distribution.
4. (a) Explain the following:
i. Dielectric constant
ii. Electric susceptibility,
iii. Electric Polarization and
iv. Polarizability.
(b) Write notes on:
i. Ferro-electricity and
ii. Piezo-electricity.
5. (a) What is Meissner effect? Explain.
(b) Describe the difference between Type-I and Type-II superconductors.
(c) The critical field for niobium is 1 × 105 amp/m at 8 K and 2 × 105 amp/m at absolute zero. Find the transition temperature of the element.
6. (a) Distinguish between spontaneous emission and stimulated emission

(b) Distinguish between homo-junction semiconductor laser and hetero-junction semiconductor laser.
(c) A semiconductor diode laser has a peak emission wavelength of 1.55 μm. Find its band gap in eV.
7. (a) Derive the expressions for
i. acceptance angle and
ii. numerical aperture, of an optical fiber.
(b) Describe different types of fibers by giving the refractive index profiles and
propagation details.
8. (a) How the physical and chemical properties of nano-particles vary with their
(b) Write the important applications of nanomaterials

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