 MORE IN Engineering Physics
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INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

1 (a) Write the assumption of quantum theory of radiation and deduce Rayleigh-Jeans law from Planck's law
5 M
1 (b) Give four important properties of meter waves
4 M
1 (c) Set up time independent Schrodinger wave equation in one dimension
7 M
1 (d) Calculate the energy in eV, for the first excited state of an electron in an infinite potential well of width 2A
4 M

2 (a) State de Broglie hypothesis and show that the group velocity of the de Broglie waves of a particle is equal to the velocity of the particle
5 M
2 (b) State and explain Heisenberg uncertainty principle
5 M
2 (c) Explain in brief the properties of wave function. If the wave function of particle in an infinite potential box of width 'a' is Ψ=Bsin (n π x/a) where x is the position and it is the quantum number, find B
6 M
2 (d) The wavelength of fast neutron of mass 1.65× 10-27 kg is 0.02 nm. Calculate the group velocity and the phase velocity of its de Broglie waves
4 M

3 (a) Obtain an expression for the conductivity of an metal from quantum mechanic considerations
6 M
3 (b) Show that the Fermi level of an intrinsic semiconductor lines in the middle of the forbidden energy gap.
5 M
3 (c) Explain the temperature dependence of resistivity of metal and state Matthiessen's rule.
5 M
3 (d) Calculate the probability of an electron occupying an energy level 0.02 eV above the Fe level at 300k
4 M

4 (a) Define the terms drift velocity, mean free path mean collision time and relaxation time.
4 M
4 (b) Explain Hall effect, Arrive at the equation for Hall coefficient in terms of Hall voltage current through the specimen
8 M
4 (c) Describe Maglev Vehicle
4 M
4 (d) Calculate the concentration at which the acceptor atoms must be added to a Germanium sample to get a p-type semiconductor with conductivity 0.15 per ohm-meter. Given the mobility of holes=0.17 m2/Vs
4 M

5 (a) Derive an expression for the radiant energy density under thermal equilibrium using Einstein's coefficients
7 M
5 (b) With suitable ray-diagram, explain the principle construction of a holographic images
5 M
5 (c) Give an account of point to point communication system using optical fibers
4 M
5 (d) The angle of acceptance of an optical fiber kept in air is 30, find the angle of acceptance when the fiber is in medium of refractive index 4/3
4 M

6 (a) Discuss the requisites and the conditions for a laser system.
6 M
6 (b) Define angle of acceptance and numerical aperture. Obtain an expression for the numerical aperture of an optical fiber.
6 M
6 (c) Explain measurement of pollutant in atmosphere using lasers
4 M
6 (d) A 5W pulsed laser emits light of wavelength 694 nm. If the duration of each pulse is 20ns, calculate the number of photons emitted per pulse
4 M

7 (a) Mention the geometrical configuration of the seven crystal system
7 M
7 (b) Sketch and describe the Perovskite structure
5 M
7 (c) Derive Bragg's equation
4 M
7 (d) The atomic radius of gold is 0.144nm. Determine the interplanar distance for (110) plane assuming that gold belongs to FCC system
4 M

8 (a) With the help of vector diagram explain the terms basis vectors lattice vector, interfacing angles and crystal parameters of a spade lattice.
6 M
8 (b) Derive an expression for interplanar distance in terms of Miller indices
5 M
8 (c) Define coordination number and packing factor. Compute the packing factor for BCC crystals
5 M
8 (d) In a calcite crystal, second order Bragg's reflection occur from planes with d-spacing 3A, at a glancing angle 24°. Calculate the path difference between x-rays reflected from the two adjacent planes. Also calculate the wavelength of the x-rays
4 M

9 (a) Define shock waves. Mention its properties
6 M
9 (b) What are nanomaterials? Outline the structure of carbon nano tube.
6 M
9 (c) What is scanning electron microscope? Mention its three applications
4 M
9 (d) The distance between the two pressure sensors in a shock tube is 100mm. The time taken by a shock wave to travel this this distance is 200 microsecond. If the velocity of sound under the same conditions is 340m/s, find the Match number of the shock wave
4 M

10 (a) Define Match number, subsonic waves and supersonic waves
3 M
10 (b) Discuss the basics of conservation of mass, momentum and energy
9 M
10 (c) Explain the sol-gel method of preparing nanomaterials
4 M
10 (d) In a scanning electron microscope, electron are accelerated by an anode potential difference of 60 kilo volt. Estimate the wavelength of the electrons in the scanning beam
4 M

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