ENGINEERING PHYSICS-1

SUBJECT CODE- 182101(PH2111)(2009-2010)

(Common to all branches of B.E. & B.Tech.)

Short Answer Question

PART-A

UNIT I - ULTRASONICS



1. What is an Ultrasonic wave? Mention its properties.

2. Name the methods by which Ultrasonic waves are produced?

3. Define Magnetostriction effect?

4. What are the disadvantages of magnetostriction oscillator?

5. Define Piezo Electric effect?

6. What is the main difference in the quality of ultrasonic waves produced by Piezo electric and magnetostriction method?

7. What is Inverse Piezo electric effect?

8. What are the advantages of Piezo electric oscillators?

9. What are the demerits of the Piezo – electric oscillator?

10. What is an acoustic grating?

11. Name any four methods of detection of ultrasonic waves.

12. Give the important applications of ultrasonics.

13. What is Cavitations? Mention its uses.

14. What is the principle of SONAR?

15. How can SONAR be used to find depth of the sea?

16. What is sonogram?

17. What are the methods to detect the ultrasonic waves?

18. Write a short notes on sonar

19. What is Coagulation?

20. State any four use of ultrasonic.

21. Define Non-destructive testing.

22. What is A-scan?

23. What is B- Scan?

24. What is C- Scan?

25. Write any two medical applications of Ultrasonics.



UNIT II - LASERS



26. What is Laser? What are its characteristics?

27. Distinguish between Spontaneous and stimulated emission

28. What is Stimulated emission?

29. What is Spontaneous emission?

30. What is Stimulated absorption?

31. What are Einstein’s coefficients?

32. Define population Inversion.

33. Define normal population.

34. What is pumping action?

35. What are the conditions to achieve the laser action?

36. Distinguish between Four level and three level lasers.

37. Compare the characteristics of laser with ordinary thermal source of light.

38. What are the three important components of laser device?

39. How lasers are classified? or Mention the various types of lasers.

40. What is Nd – YAG laser?

41. What are the applications of Nd- YAG laser?

42. What is CO2 laser?

43. What is the active medium in CO2 laser?

44. What are the applications of CO2 laser?

45. What is Semiconductor laser?

46. What are the applications of Semiconductor laser?

47. Name any four uses of laser in medical field.

48. Name any four uses of laser in engineering field.

49. What is an optical resonator?

50. Define Active centre and Active medium?

51. What is hologram?



UNIT III – FIBRE OPTICS & APPLICATIONS



52. Define Optical Fiber.

53. What is the principle of optical fiber?

54. What are the conditions for total internal reflection?

55. What is meant by mode?

56. Define numerical apertures.

57. Define acceptance angle.

58. What is single mode fiber?

59. What is multi mode fiber?

60. What is step index fiber?

61. What is graded index fiber?

62. What is a wave guide?

63. What are the types of optical fibers based on number of modes?

64. What are the types of optical fibers based on refractive index profile?

65. Mention the components involved in fiber optical system?

66. Distinguish between step and graded index fiber.

67. Distinguish between single mode and Multi mode fiber.

68. Write a short note on losses in optical fiber.

69. What is intrinsic absorption?

70. Distinguish between Active and Passive fiber.

71. What is sensor? What are the good conditions for sensor?

72. Define Splicing.

73. What is dispersion?

74. What is attenuation?

75. What are the advantages of the fiber optical communication system?

76. Write the applications of fiber optical system.

77. Define Chromatic dispersion

78. Define Intermodel dispersion

79. What are the industrial applications of ultrasonics?

80. Distinguish between hologram and photography.

81. What are the detectors that are used in fiber optic communication?

82. Write a short note on temperature sensor

83. Write a short note on pressure sensor









UNIT IV – QUANTUM PHYSICS



84. What is Black body radiation?

85. What is Schrödinger wave equation?

86. Write the postulates of Planck’s Quantum theory.

87. Write down Planck’s radiation formula.

88. State Wien’s displacement law.

89. State Rayleigh – Jean’s law.

90. State Heisenberg’s uncertainty principle.

91. What is Compton Effect?

92. What is Compton wavelength?

93. What are minimum and maximum values of Compton shift?

94. What is a wavefuntion?

95. Mention some of the physical significance of the wave function.

96. What are “Eigen values” and “Eigen functions”?

97. What is meant by Photon? Give its properties.

98. What are de- Broglie wave or matter waves?

99. Explain degenerate states and non-degenerate states.

100. What is Schrödinger wave equation?

101. Write down Schrödinger time independent and dependent wave equations.

102. Write the energy value of the particle in one dimensional box.

103. Mention some important applications of quantum mechanics.







UNIT V –CRYSTAL PHYSICS



104. Define crystal.

105. Define unit cell.

106. Define atomic radius.

107. Define co-ordination number.

108. Define space lattice.

109. What are lattice parameters?

110. What is a primitive cell?

111. What is non-primitive cell?

112. Define Basis.

113. What is crystallography?

114. What are miller indices?

115. Define Bravais lattice.

116. Define burgers vectors.

117. What is dislocation?

118. Define Screw dislocation.

119. Define edge dislocation.

120. Define Frenkel and Schottky defect.

121. Define Substitution impurity defect.

122. Define interstitial impurities.

123. Define Stacking faults.

124. Define grain boundaries.

125. Draw (111) plane in simple cubic.

126. Draw (101) plane in simple cubic.

127. Define interplanar distance.

128. Define polymorphism and allotropy.

129. Write the atomic radius, co-ordination number for diamond structure.

130. Define packing fraction

131. Name seven crystal systems.



Part-B

UNIT I –ULTRASONICS



1. What is Magnetostriction effect? Explain Magnetostriction Oscillators.

2. What is piezo electric Effect? Explain piezo electric Oscillators.

3. Determine the velocity measurement of ultrasonic waves in liquids.

4. Write a short note on (i) Detection of ultra sonic (ii) Cavitation (iii)Sonar

5. Explain with neat sketch the application of ultrasonic in cardiology.

6. How ultrasonic waves are detected? Explain.

7. Give the industrial applications of ultrasonic waves in detail.

8. Give the medical applications of ultrasonic waves in detail.

9. Explain Non-destructive testing method in detail.

10. Explain ultrasonic imaging systems in detail.



UNIT II - LASERS



11. Describe the construction and working of Nd-YAG laser.

12. Describe the construction and working of Co2 laser.

13. Describe the construction and working of semiconductor laser.

14. Describe the construction and working of He-Ne laser.

15. Explain with neat sketch the construction and reconstruction of holographic image.

16. Explain Einstein coefficient and then prove ratio of stimulated to spontaneous emission is given by 1/ehv/kT-1.

17. Discuss the applications of laser in various fields.





UNIT III –FIBER OPTICS AND APPLICATIONS





18. Derive the expression for acceptance angle and Numerical aperture of an optical fiber.

19. Write a short note on (i) Principle of light in optical fiber (ii) Double crucible method.

20. Classify the optical fibers on the basis of materials, modes of propagation and refractive index difference.

21. Write a shote note on (i) step index fiber (ii) Graded index fiber.

22. Write a short note on (i) Single mode fiber (ii) Multimode fiber.

23. Write a short note on (i) losses in optical fiber (ii) Fiber optic communication system.

24. What are Fiber splices? Explain in detail.

25. Write a short note on (i) Pressure and Intensity sensor (ii) displacement sensor.





UNIT IV – QUANTUM PHYSICS



26. What is Black Body radiation .Derive the expression for Planck theory of black body radiation?

27. What is Compton Effect? Derive the expression for the Compton shift wavelength.

28. Derive the expression for schroedinger time independent and dependent wave equation.

29. Explain particle in one dimensional box and also explain three dimensional effects.

30. Explain (i) Transmission electron Microscope (ii) Scanning Electron Microscope.



UNIT V – CRYSTAL PHYSICS



31. Show that packing fraction for simple cubic is 52%

32. show that packing fraction for body centered cubic is 68%

33. Show that packing fraction for face centered cubic is 74%

34. What is Hcp structure explain c/a ratio is 1.632 and also packing fraction is 74%

35. What are miller indices? Show that interplanar distance is d=a/√(h2+k2+l2).

36. Write a short note on (i) Diamond Structure (ii) Nacl structure (iii) Bravais lattice

37. Explain various types of defects in crystals in detail.