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8 Reg. No. : 32 Question Paper Code : 11017 B.E./B.Tech. DEGREE EXAMINATION, JUNE 2011. 84 Common to all B.E./B.Tech. First Semester 182101 — ENGINEERING PHYSICS — I (Regulation 2010) Time : Three hours 32 Answer ALL questions. PART A — (10 × 2 = 20 marks) Maximum : 100 marks 84 1. State any two properties of ultrasonic waves. 2. An ultrasonic source of .07 MHz sends down a pulse towards the seabed which returns after 0.65 sec. The velocity of sound in seawater is 1700 m/s. Calculate the depth of the sea. 3. What are the characteristics of LASER? 32 4. Give the wavelengths of light emitted by the CO2 laser. 5. Define attenuation in an optical fibre and mention its unit. 4 6. Calculate the numerical aperture and acceptance angle of an optical fibre having n1 = 1.49 and n2 = 1.44 . 7. State Wien’s displacement law of black body radiation. 28 8. Mention any two limitations of Transmission Electron Microscope (TEM). 9. What are Miller indices? 10. Define Polymorphism and allotrophy.43
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8 PART B — (5 × 16 = 80 marks) 32 11. (a) (i) How will you produce ultrasonic waves using piezo electric oscillator? (12) (ii) A quartz crystal of thickness .005 m is vibrating at resonance. Calculate the fundamental and first overtone frequency, given the Young’s modulus for quartz as 7.9 × 1010 N/m2 and density of quartz 84 2650 kg/m3. (4) Or (b) Describe the following : (i) Industrial applications of ultrasonics. (8) 12. (a) (ii) (i) 32 Different modes of scanning used in ultrasonic imaging technique. (8) Derive expressions for the Einstein’s coefficient of spontaneous and 84 stimulated emissions. (8) (ii) Explain the construction and working of He-Ne laser. (8) Or (b) (i) Describe the construction and working of homo-junction and hetero- junction semiconductor lasers. (10) 32 (ii) Define holography. Explain the working principle of construction of a hologram with a neat sketch. What are its applications? (6) 13. (a) (i) Obtain expressions for numerical aperture and acceptance angle of 4 an optical fibre. (8) (ii) Describe the double crucible technique of the production of fibre cables. (8) 28 Or (b) (i) Write short notes on temperature and displacement sensors. (8) (ii) Describe the optical fibre communication with a neat block43 diagram. (8) 2 11017
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8 14. (a) Write down the Schrodinger’s wave equation for a particle in a box. Solve it to obtain eigen function and show that eigen values are discrete. (16) 32 Or (b) (i) Explain the working of Scanning Electron Microscope with neat diagram. (12) 84 (ii) Calculate the de Broglie wavelength of a proton whose kinetic energy is 1 MeV. (4) 15. (a) Show that the packing density of Hexogonal Closed Packed (HCP) system is the same as that of Face Centered Cubic (FCC) system. (16) Or (b) (i) 32 Obtain the number of atoms per unit cell, the coordination number, atomic radius and the packing density of Body Centered Cubic (BCC) system. (8) (ii) Write short notes on point defects. (8) 84 ————————— 4 32 2843 3 11017
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