B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2011. Common to All B.E./ B.Tech. 182101 — ENGINEERING PHYSICS – I First Semester (Regulation 2010)

B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2011.

Common to All B.E./ B.Tech.

182101 — ENGINEERING PHYSICS – I

First Semester

(Regulation 2010)

Time : Three hours Maximum : 100 marks

Answer ALL questions.

PART A — (10 ´ 2 = 20 marks)

1. What is called the cavitation effect of ultrasonic waves?

2. A SONAR system receives the echo after 1.5 s from signal-launch in sea water. Find the depth of

the sea if the ultrasonic velocity in sea water is l490 m/s.

3. What is population inversion in laser systems?

4. Compare normal photography and holography.

5. Distinguish between step-indexed fibre and graded indexed fibre.

6. What is called splicing of optical fibre?

7. What are matter waves?

8. What is the physical significance of wave function of a matter wave?

9. Identify the crystal structures with the following lattice parameters :

(a) a=b=c: a= b= ¹ g 90°

(b) a=b ¹ c a= b=90°, g=120°.

10. What is known as Burgers vector of a dislocation?

PART B — (5 ´ 16 = 80 marks)

11. (a) (i) Explain the principle, construction and working of a magneto-striction oscillator to

produce ultrasonic waves. (10)

(ii) Discuss the industrial applications of ultrasonics. (6)

(b) Explain, with necessary schematic diagrams, the different ultrasonic scan modes. (16)

12. (a) Deduce Einsteins rate equations and hence obtain expressions for the famous A and B

coefficients for a two level system. What are the important outcomes of the theory? (12+4)

(b) Explain the working of a Nd:YAG laser along with the energy level scheme and schematic 

device diagram. (16)

13. (a) (i) Derive expressions for the numerical aperture and maximum acceptance angle of an

optical fibre. (10)

(ii) Explain the working of a fibre-optic communication system with neat schematic diagram. (6)

(b) (i) With a neat schematic diagram, explain the working of a fibre-optic endoscope in medical 

field. (10)

(ii) What are active and passive sensors? Explain, with a neat diagram, the working of any one 

passive sensor. (2+4)

14. (a) What is called the Compton effect? Discuss the theory and experimental study of it. List the

important outcomes of the results. (2+12+2)

(b) Discuss the theory of particle-in-a-box problem in one-dimension and explain the results. (16)

15. (a) (i) Outline the various steps of obtaining the Miller indices of crystal planes. Also sketch

(210) and (212) planes separately. (2+4)

(ii) Derive an expression for the inter-planar distance of a cubic crystal. (10)

Or

(b) Deduce the atomic radii, number of atoms per unit cell and packing factors of BCC and

FCC crystals. (16)