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USN
on, Dec.20l5lJan.20l6
Engineering Physics
hrs.
Max. Marks:100
Answer any FIVEfull questions, selecting atleast ONEfult questionfrom each part. 2. Physical constants : Velocity of light, C:3 x 708 m/s ; Phnk's constunt, h:6.625 * rct'"lS ; Muss of electrons, m :9.11 x l[3tkg ; Boltzmann's constant, K: 1.38 x IA23J/K. Avogadro number, Nl: 6.02 x t d6tX mole.
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State Heisenberg's uncertainity principle. Using uncertainity principle. Explain the non (07 Marks) existence of electron in the nucleus. Using time independent Schrodinger's wave equation, obtain the expression for the normalized wave function for a particle in one dimensional potential well of infinite height. (09 Marks)
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(05 Marks) Define phase velocity and group velocity. Derive a relation between the What is the physical interpretation of wave function? Explain the nature of eigen values and (06 Marks) eigen functions. (06 Marks) Explain Wein's law and Rayleigh - Jean's law. Discuss their drawbacks. Calculate the de - Broglie wavelength associated with an electron carrying energy 2000 eV. (03 rllarks)
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q '" ;E it.= >'!i " .,.,;".:i PART - 2 S ;" ;= gU 3 a. Explain the probability of occupation of various energy state by electron at T : 0 K and EE (06 Marks) T > 0 K on the basis of Fermi factor. ! a b. Define Hall Effect and HallVoltage. Derive an expression for Hall coefficient. (06 Marks) :: "_ *n (04 Marks) , #": c. Explain BCS theory of Super conductivity. x E - {:-n d. Find the relaxation time of conduction electrons in a metal of resistivity 1.54 10-8 Om, if (04 Marks) the metal has 5.8 , 1028 electrons/m3. E *. -
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4 a. Discuss different types of super conductors. b. Explain Fermi - energy and Fermi - factor. c. Explain failure of Classical free olectron theory. d. Calculate the Fermi velocity for the free electrons in gold. Given Er : 5.53eV. I
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3
Derive an expression for energy density in terms of Einstein's coefficients. (08 Marks) (08 Marks) b. Explain the construction and working of carbon dioxide laser device. fraction of its initial c. The attenuation of light in an optical fiber is 3.6 dB/km. What l+ttegpty remains after i) 1 km ii) after 3 km. ,"@4alVihrks)
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(08 Marks) (06 Marks) types of optical Discuss different An optical fiber has a numerical aperture of 0.32. The refractive index of cladding is 1.48. Calculate the refractive index of the core, the acceptance angle of the fiber and the fractional (06 Marks) index change.
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(05 Marks) Obtain the expression for inter planar spacing of a cubic crystal. (06 Marks) packing for SC, FCC and BCC lattices. factor b. Calculate the atomic (06 Marks) c. Write a note on Perovskite structure. d. A sodium chloride crystal is used as a diffraction grating with X - rays. For the d111 spacing of the chloride ions the angle of diffraction 20 is27.50.If the lattice constant of the crystal is (03 Marks) 0.563nm, what is the wavelength of X - rays?
interplanar spacing in a crystal. Discuss the principle and working of Liquid Crystal Display. Draw (100) , (110), (011) and (111) planes in a Simple cubic crystal.
Distinguish acoustic, subsonic and supersonic waves. b. Explain the preparation of nano structure using Sol - Gel method. c. Write a note on Carbon Nanotubes. d' What are Shock waves? Mention few applications of Shock wave.
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(08 Marks) Explain the principle, construction and working of Reddy Shock tube. method. Mention b. Explain the preparation of nano structures using Top - Down approach (06 Marks) any two properties of nano materials. (06 Marks) of Scanning Electron Microscope. c. Explain the construction and working a.
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