Hall Ticket No Question Paper Code: AHSB04
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
Four Year B.Tech I Semester End Examinations (Regular) November, 2018
Regulation: IARE R18
WAVES AND OPTICS
Time: 3 Hours (Common to AE ME ECE) Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. Describe Davisson-Germer experiment to demonstrate the wave character of electrons.
What will be the KE of an electron if its de Broglie wavelength equals the wavelength of the
yellow line of sodium 58960A. The rest mass of electron is m0 9.1x10􀀀31kg and h 6.63x10􀀀34
J-s.
2. Show that the energy of a particle enclosed in a rigid one dimensional infinite potential box is
quantized.
Find the lowest energy that an electron (mass =9.1 x Kg) can have if confined to move
along the edge of an impenetrable box of length 4 x
UNIT II
3. Discuss Kronig Penney model and hence show that the energy spectrum of an electron contains
a number of allowed energy bands separated by forbidden bands
Draw Energy band diagram for conductor, semiconductor and insulator.
4. What is Hall effect? Show that the Hall coefficient is RH VHt
IB
A silicon plate of thickness 1 mm, breadth 10mm and length 100mm is placed in a magnetic
field of 0.5 Wb/m2 acting perpendicular to its breadth. If A current flows along its length.
Calculate hall voltage developed. RH 3.66 x
UNIT III
5. With a neat diagram discuss construction, working and uses of He-Ne Laser.
Calculate the wavelength of emission from GaAs semiconductor laser whose band gap energy is
1.44 ev (Plank's constant is 6.625 x and charge of an electron is 1.6 x C.)
Page 1 of 2
6. Define numerical aperture. Derive an expression for acceptance angle of an optical fiber.
Discuss the classification of optical fiber based on the refractive index
UNIT IV
7. Derive an expression for fringe width from Young's double slit experiment. Show that fringe
width of bright and dark fringe is equal.
In Young's double slit experiment a 2cm space on the screen placed at 200cm contains 20 fringes.
Find the fringe width and slit separation if the wave length of light used is 51000A.
8. Describe Fraunhofer diffraction due to a single slit and deduce the position of the maxima and
minima.
Explain the construction and working of Michelson interferometer.
UNIT V
9. What is simple harmonic motion? Derive a relation for displacement, time period, velocity and
acceleration of a particle executing simple harmonic motion.
Define damped harmonic oscillation? Derive wave equation for damped oscillation.
10. What are transverse and longitudinal wave? Give one example of each. Discuss the terms
associated with a wave
i. Frequency
ii. Time period
iii. Wave length
The equation of certain traveling waves is 0.0450 sin(25.12x 37.68t 0.523) where x
and y are in meters, and t in seconds.
Determine
i. Amplitud
ii. Wave number
iii. Wavelength
iv. Angular frequency
v. Frequency
vi. Phase angle