Download MODEL EXAM physics-Sem1 29-11-2013 SET 2

LOYOLA – ICAM
COLLEGE OF ENGINEERING AND TECHNOLOGY (LICET)
Loyola College Campus, Nungambakkam , Chennai – 34
Branch: Common to All Branch
Date: 27.11.2013
Semester: I
Time : 08.00 – 11.00 Am
MODEL EXAMINATION
ENGINEERING PHYSICS – I (PH2161)
PART –A
Answer all questions
(2 X 610= 20)
1. Differentiate crystalline and non-crystalline materials.
2. Draw the crystal planes with Miller indices (001) and (010).
3. What do you infer from stress- strain diagram?
4. Can Lee’s disc method is used for good conductors?
5. What is the physical significance of the wave function? (write any four)
6. State Rayleigh-Jeans law. What are its limitations?
7. Define absorption coefficient (α).
8. Mention some of the applications of ultrasonic waves.
9. What are the characteristics of LASER.
10. What are the conditions to be satisfied for total internal reflection?
PART – B
(16 x 5 = 80)
11. (a)(i).Describe a HCP structure. Show that for HCP structure C/a= √8⁄3 and hence calculate
the packing fraction for HCP structure.
(ii) An element has HCP structure. If the radius of the atom is 1.605Ǻ, find the volume of the unit
cell?
(12+4)
OR
11(b).With a neat sketch, explain Czochralski technique and Bridgeman’s technique for
crystal growth.Give their merits and demerits
(12+4)
12(a)(i).Define the terms ‘Stress and Strain’. Derive an expression for the depression of a cantilever.
Using that expression, how will you determine the Young’s modulus of the material of the
cantilever?
(ii).A wire of length 3m and cross section 6.25 x 10-5m2 is found to stretch 3x10-3m under a
tension of 1.2 x103 N. What is the Young’s modulus of the material of the wire? (12 + 4)
OR
12(b)(i) With a neat sketch, explain the experimental method used to determine the thermal
conductivity of a rubber tube based on the principle of radial flow of heat.
(ii).For a rubber tube, internal radius is 0.25 cm and external radius is 0.35cm. The inner temperature
is 370C and outer temperature is 300C. What is the temperature at a distance of 0.5 cm from the
axis of rubber tube? (12+4)
13(a)(i).What is Compton effect? Derive an expression for the frequency of the scattered photon in
terms of frequency of incident radiation.
(ii). In Compton scattering, the incident photons have wavelength of 0.5nm. Calculate the wavelength
of scattered radiation, if they are viewed at an angle of 450 to the direction of incidence.
(12+4)
OR
13(b)(i).What is the principle of electron microscopy? With a schematic diagram, explain the
construction and working of a Scanning Electron Microscope.
(ii) Calculate the equivalent wavelength of an electron moving with a velocity of 3x107m/s.
(12+4)
14(a)(i).What is reverberation time? Derive an expression for the rate of growth and decay of
Sound in an auditorium, with necessary graph.
(ii).The volume of a hall is 800m3. If the reverberation time of the hall is required to be
maintainedat 1.3 sec, what should be the total absorption in the hall?
(12+4)
OR
14(b)(i).With a schematic diagram, describe the construction and working of Ultrasonic flaw
detector for non-destructive testing by reflection mode.
(ii)Explain Ultrasonic A- Scan and B-Scan display used for data presentation.
(12+4)
15(a)(i).Distinguish between Spontaneous emission and Stimulated emission. Describe the
construction and working of CO2laser with energy level diagram.
(12+4)
(ii) A CO2 laser source emits light of wavelength 9.6µm and has an output power of
10Kw. How many photons are emitted in each second by this laser while operating?
OR
15(b)(i).Derive an expression for the numerical aperture and acceptance angle of an optical
fiber.
(ii).Calculate the numerical aperture and acceptance angle of an optical
fiber, whose core and cladding are made of materials of refractive index 1.55 and
1.50 respectively.
(12+4)