B.E-B.E Civil Engineering 1st Sem PH 6151 ENGINEERING PHYSICS -1 Code :37006(Anna University Chennai-2014)
B.E/B.Tech. DEGREE EXAMINATION, JANUARY 2014.
First Semester Civil Engineering
PH 6151 ENGINEERING PHYSICS 1
(Common to all branches)
(Regulation 2013)
Question Paper Code : 37006
Time : Three hours Maximum : 100 marks
Answer ALL questions.
PART A (10 x 2 = 20 marks)
1. What is a primitive cell? Give and example.
2. Name few techniques of crystal growth from melt.
3. A copper wire of 3 m length and 1 mm diameter is subjected to a tension of 5N.
Calculate the elongation produced in the wire if the Young’s modulas of copper is 120 GPa.
4. State Newton’s law of cooling.
5. Find the lowest energy of the electron confined to move in a one dimensional box of
length 1Å.
Given. me = 9.1x10-31 kg
/\ = 6.625x10-34 Js.
6. Write the principle of transmission electron microscope.
7. State WeberFechner law.
8. Are ultrasonic waves electromagnetic waves in nature? Explain.
9. Can a two level system can be used for the production of laser? Why?
10. Write any four major advantages of optical fibre communication over other
communication systems.
PART B (5 x 16 = 80 marks)
11.(a)
(i) What is packing factor? Prove that the packing factor of HCP is 0.74. (2+10)
(ii) Copper has fcc structure and its atomic radius is 1.273Â.
Find
(1) Lattice parameter and (2)
(2) Density of copper. (2)
Given
Atomic weight of copper = 63.5
Avagadro’s number = 6.026x1026 mol-1
OR
11.(b)
(i) Describe Bridgemann method of crystal growth. (8)
(ii) Briefly explain the Chemical Vapour Deposition (CVD) method. (8)
12.(a)
(i) Derive an expression for depression at the free end of cantilever due to Load. (12)
(ii) Give an account of Ishape Girders. (4)
OR
12.(b)Describe with theory Lee’s disc method of determination of thermal conductivity
of a bad conductor. (16)
13.(a)
(i) Derive Plank’s law of radiation. (12)
(ii) In a Compton scattering experiment the incident photons have a wavelength of 3Â.
What is the wavelength of scattered photons if they are viewedat an angle of 600 to
the direction of incidence? (4)
Given : me = 9.1x10-31 kg
/\ = 6.625x10-34 Js.
c = 3x108 ms-1
OR
13.(b)Write the principle, working, advantages and disadvantages of scanning electron
microscope. (16)
14.(a) State and explain Sabine’s formula for reverberation time of a hall. Derive Sabine’s
formula for reverberation time. (16)
OR
14.(b)
(i) Explain Piezoelectric effect. Describe the piezoelectric method of producing
ultrasonic waves. (2+10)
(ii) Calculate the velocity of ultrasonic waves in a liquid in an acoustic grating
experiment using the following data. (4)
Wavelength of light used = 600nm.
Frequency of ultrasonic waves = 100MHz
Angle of diffraction = 5o
15.(a)
(i) Describe the construction and working of CO2 laser and their uses. (14)
(ii) For a semiconductor laser, the bandgap is 0.9eV. What is the wavelength of light
emitted from it. Use the following data: (2)
/\ = 6.625x10-34 Js.
c = 3x108 ms-1
OR
15.(b) Explain the construction and working of displacement and Temperature
and fibre optic sensors. (8+8)
| Earning: ₹ 10.00/- |
