2010 anna university chennai b-physics i

8/8/2019 2010 Anna University Chennai B-Physics I

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2010 Anna University Chennai B.E PH2111 Engineering Physics I

Question paper

Course: B.E B.E University/board: Anna University Chennai

B.E./B.Tech.Degree Examinations, November/December 2010Regulations 2008First Semester

Common to all branchesPH2111 Engineering Physics I

Time: Three Hours Maximum: 100 Marks

Answer ALL QuestionsPart A - (10 x 2 = 20 Marks)1. List down the disadvantages of piezoelectric eect.2. Compare transmission and refection modes of non destructive testing using ultra-sonics.3. Why i s population inversion necessary to achieve lasing?4. How is electrons and holes confinement made in the active region of hetero junctionlaser?5. What are the dierent types of classification of optical fibres?6. Explain dispersion in an optical fiber.7. Define black body and black body radiation.8. What is meant by wave function?9. An element has a HCP structure. If the radius of the atom i s 1.605A, nd theheight of unit cell.10. What is meant by a `Schottky pair'?

Part B - (5 x 16 = 80 Marks)

11. (a) With a neat diagram explain the method of production of ultrasound usingpiezoelectric crystal. (Marks 16)OR11. (b) (i) With a neat diagram, discuss the principle and inspection method of ul-trasonic aw detector. (Marks 12)(ii) Calculate the velocity of ultrasonic waves in water using acoustic grat-ing. The frequency of the ultrasonic wave generated by transducer is 2MHz. The DIration angle measured i s 8'45" in the third order difrac-tion pattern. Wavelength of laser light used in this experiment i s 6328A.(Marks 4)


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12. (a) Discuss the Einstein's theory of stimulated absorption, spontaneous and stim-ulated emission of radiation. What are the conditions for light amplification?(Marks 16)OR12. (b) (i) What is hologram? What are the necessary steps involved in recording

and reconstruction of a hologram? (Marks 12)(ii) Compare holography with photography. (Marks 4)

13. (a) (i) Explain the basic structure of an optical fibre and discuss the principle of transmission of light through optical fibers. (Marks 5)(ii) Derive an expression for numerical aperture. (Marks 5)(iii) Briey discuss a technique of optical fiber drawing. (Marks 6)OR13. (b) Explain the concept of optical fiber sensors and describe in detail about anytwo sensors. (Marks 6 + 10)

14. (a) (i) What i s meant by matter wave? (Marks 2)

(ii) Derive an expression for the wavelength of matter wave. (Marks 8)(iii) Describe an experiment that veriest the existence of matter waves. (Marks 6)OR14. (b) Solve Schrodinger's wave equation for a particle in a box (one dimensional)and obtain the energy and eigen function. (Marks 16)

15. (a) (i) Define atomic packing factor. (Marks 2)

(ii) Calculate the number of atoms, atomic radius, coordination number andatomic packing fraction for BCC and FCC structures. (Marks 10)(iii) The distance between successive planes of Miller induces (111) is 2.078Afor a metal having FCC structure. Find the atomic radius and volume of

its unit cell. (Marks 4)OR15. (b) (i) Define the terms polymorphism and allotrope. (Marks 2)(ii) Explain in detail the crystal defects and their types. (Marks 14)


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2010 Anna University Chennai B.E PH2111 Engineering Physics I

Question paper

Course: B.E B.E University/board: Anna University Chennai

B.E./B.Tech. DEGREE EXAMINATIONS, MAY/JUNE 2010

Regulations 2008First Semester

Common to all branches

PH2111 Engineering Physics I

Time: Three Hours Maximum: 100 MarksAnswer ALL Questions

Part A - (10 x 2 = 20 Marks)

1. Mention any two properties of ultrasonic waves.2. What i s the principle of pulse echo system?3. What are the conditions needed for laser action?4. What is holography?.5. DeNE acceptance angle of a bee.6. Give the applications of the bee optical system.7. Calculate DE Brogue wavelength of an electron moving with velocity 107 m/s.8. Explain degenerate and non-degenerate states.9. Calculate the est and second nearest neighbor distances in the body centered cubic unitcell of sodium, which has lattice constant of 4:3 1010 m.10. What i s meant by Frankel imperfection?

Part B - (5 x 16 = 80 Marks)

11. (a) (i) What are magnetosphere and piezoelectric eetc? (Marks 4)(ii) Write down the complete experimental procedure with a neat circuit diagram of producing ultrasonic waves by piezoelectric eetc. (Marks 12)OR11. (b) (i) What i s an acoustic grating? How i s it used in determining the velocity of ultrasound?(Marks 2 + 6)


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(ii) Explain the process of non-destructive testing of materials using ultrasonic wavesby pulse-echo method. (Marks 8)

12. (a) (i) Derive the relation between the probabilities of spontaneous emission and stim-ulated emission in terms of Einstein's cucents. (Marks 8)(ii) Explain the following pumping mechanisms.

(1) optical and(2) electric discharge. (Marks 8)OR12. (b) (i) With a neat sketch, explain the construction, principle and working of CO2 laser.(Marks 14)(ii) Mention four applications of lasers in materials processing.(2)

13. (a) (i) Explain the basic structure of an optical bee and discuss the principle of trans-mission of light through optical bees. (Marks 5)(ii) Derive an expression for numerical aperture. (Marks 5)(iii) Briey discuss a technique of optical bee drawing. (Marks 6)

OR13. (b) (i) With a neat diagram, give an account on displacement sensors. (Marks 8)(ii) Give an elaborate account on losses in optical bees. (Marks 8)

14. (a) (i) What is Compton eect? Derive an expression for the change in wavelengthsewreed by an X-ray photon, when it collides with an electron. (Marks 2 + 12)(ii) An electron at rest i s accelerated through a potential of 2 kV. Calculate the deBroglie wavelength of matter wave associated with it. (Marks 2)OR14. (b) (i) Solve the Schrodinger's wave equation for a free particle of mass m moving withina one dimensional potential box of width L to obtain eigenvalues of energy andeigenfunctions.

(Marks 11)(ii) Find the eigenvalues of energies and eigenfunctions of an electron moving in aone dimensional potential box of intine height and 1 A of width. Given that m= 9.11 1031 kg and h = 6.63 1034 J. (Marks 5)

15. (a) (i) What are Miller induces? Mention the steps involved to determine the Millerinduces with example. (Marks 2 + 4)(ii) The material zinc has HCP structure. If the radius of the atom is14Th of thediagonal of hexagon, calculate the height of the unit cell in terms of atomicradius.(2)(iii) Show that the packing factor for HCP is 74% . (Marks 8)OR15. (b) (i) What i s Burger vector? (Marks 2)(ii) Draw Burger circuit indicating Burger vector for edge dislocation and screw dis-location. (Marks 4+4)(iii) Certain defects in crystals improve the properties of crystals. Explain. (Marks 6)

2010 anna university chennai b-physics i

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