Quiznetik

Unconventional Machine Process (UMP) | Set 4

1. Wires used in wire cut EDM are usually disposed after one usage.

Correct : A. true

2. The electrode wires are usually made form

Correct : D. brass

3. grades wire are used in automatic re-threading mechanisms.

Correct : C. harder

4. For machining of high melting point materials,            wires are used.

Correct : B. zinc coated

5. is/are used as di-electric fluid in die sink EDM process.

Correct : C. petroleum products

6. Which of the following is not the application of wire cut EDM process?

Correct : D. machining of complex shapes made of plastic

7. During mould making by wire cut EDM, it is important to harden              to counter the effects of changes in the shape of the workpiece due to heat treatment.

Correct : A. the insert

8. Which of the following machining process is usually preferred for cutting of ejectors which are used in mould making?

Correct : C. wire-cut edm

9. How many ways are there for making the fixed cores by wire cut EDM process?

Correct : A. 2

10. The selection of the manufacturing process depends upon

Correct : B. mould shape

11. The wire EDM process is used for making moulds with high drafted walls.

Correct : A. true

12. For manufacturing of complex shapes, soft electrode wires are used.

Correct : A. true

13. What is the full form of LBM in advanced machining processes?

Correct : B. laser beam machining

14. LBM offers a good solution for which material properties below?

Correct : D. all of the mentioned

15. What is the abbreviation of Laser?

Correct : B. light amplification by stimulated emission of radiation

16. Which of the following are the properties of a laser?

Correct : D. all of the mentioned

17. Laser beam machining uses which type of power sources for machining?

Correct : D. high power

18. Which of the following are different types of lasers used in Laser beam machining?

Correct : D. all of the mentioned

19. Which types of lasers are used in Laser beam machining?

Correct : C. continuous wave & pulsed mode

20. What is the wavelength value of Ruby laser used in Laser beam machining?

Correct : B. 694 nm

21. What is the wavelength value of Nd-YAG and Nd-glass lasers used in LBM?

Correct : D. 1064 nm

22. What is the wavelength value of neutral gas laser used in LBM?

Correct : A. 633 nm

23. What is the wavelength value of CO2 laser used in Laser beam machining?

Correct : C. 10.6 μm

24. What is the material removal mechanism of Laser beam machining process?

Correct : A. melt and evaporate

25. Physics of laser is very complex due to which of the reasons below?

Correct : C. scattering & reflection loss

26. What happens when the heat is diffused into bulk material?

Correct : D. all of the mentioned

27. What happens to the process efficiency if plasma plumes are formed in LBM?

Correct : C. decreases

28. Machining of LBM takes place when power density is                          than what is lost by conduction and radiation.

Correct : A. greater

29. Which of the following phenomenon take place before melting and evaporating in LBM?

Correct : D. all of the mentioned

30. What happens to the material removal rate when reflectivity is higher?

Correct : A. will decrease

31. Reflectivity of the materials depends on which of the following factors?

Correct : D. all of the mentioned

32. How much amount of incident radiation is reflected at lower power densities?

Correct : D. 90 percent

33. How are minimum energies required for plastics when compared to that required for metals?

Correct : A. lower than

34. Which of the following has high machining speeds in Laser Beam Machining?

Correct : B. non metals

35. Which of the following are the applications of Laser Beam Machining?

Correct : D. all of the mentioned

36. State whether the following statement is true or false regarding the drilling using LBM. “Compared to LBM, conventional machining is more accurate and efficient.”

Correct : B. false

37. Other non-conventional processes lay behind Laser beam machining in drilling process because of which factors below?

Correct : D. all of the mentioned

38. Laser drilling has proven to be more efficient in which of the following factors?

Correct : D. all of the mentioned

39. Which of the following are different laser drilling processes in Laser beam machining?

Correct : D. all of the mentioned

40. The hole size in direct drilling depend up on which of the factors below?

Correct : C. input power & focusing adjustments

41. Which method mentioned below is used for drilling of large size holes?

Correct : C. trepanning

42. What is the value the maximum optimum depth that can be machined using Laser drilling process?

Correct : B. 1.7 mm

43. What is the depth-to-diameter ratio obtained in drilling process using Laser beam machining?

Correct : C. 50:1

44. What is the maximum value of drilling depth in trepanning method of laser drilling process?

Correct : C. 6.4 mm

45. What is the value of minimum corner radius obtained by drilling in Laser beam machining?

Correct : B. 0.25 mm

46. Peak power should be increased in Laser drilling process by                      pulse energy.

Correct : A. increasing

47. Drilling of holes with larger pulse duration causes which effect to the holes produced?

Correct : A. enlarge holes

48. pulse energy and                    pulse duration are suitable for drilling.

Correct : C. high, short

49. Which of the following are the functions of assist gases?

Correct : D. all of the mentioned

50. Selection of assist gas depends on which of the following properties of work piece?

Correct : C. material & thickness

51. Which of the following properties of material affect the quality of holes obtained?

Correct : D. all of the mentioned

52. What range of powers are used for cutting through steel?

Correct : C. 200 to 1000 w

53. Which gas jet assisted process is suitable for most of the metals?

Correct : A. oxygen gas

54. What happens to the cutting speed with an increase in the work piece?

Correct : B. decreases

55. What is the full form of LBT in the processes of LBM?

Correct : C. laser beam texturing

56. Depth and the crater size depends on which of them below?

Correct : C. energy & dwell time of beam

57. Where are the textured surfaces used that are obtained in LBT?

Correct : D. all of the mentioned

58. The roll is                    and the laser beam is moved                  along the roll.

Correct : C. rotated, axially

59. State whether the following statement is true regarding the texturing in LBT. “In LBT, hardness of the material is a limitation to the process.”

Correct : B. false

60. Which of the following are the other applications of LBM?

Correct : D. all of the mentioned

61. How the grooves in grinding wheels are produced using laser?

Correct : C. evaporation & damage of composite

62. Work piece tilting depends on which of the following factors?

Correct : D. all of the mentioned

63. Lasers of which type are used for modification of electronic components?

Correct : D. all of the mentioned

64. Material removal rates which are about mg/pulse produces which type of holes?

Correct : A. shallow

65. Which of the following materials can be easily separated by laser scribing?

Correct : D. all of the mentioned

66. Which type of holes can be drilled using Nd-YAG laser?

Correct : C. small & large holes

67. Which type of laser can be used for direct drilling or percussion?

Correct : C. ruby & nd-yag laser

68. Which of the following lasers is used for cutting thick materials in LBM?

Correct : A. co2 + gas assisted

69. Which of the following lasers is used for slitting of thin metallic materials in LBM?

Correct : C. nd-yag

70. Which of the following lasers is used for slitting of thin plastic materials in LBM?

Correct : B. co2 only

71. Which of the following lasers is used for organics and non-metallic materials in LBM?

Correct : B. pulsed co2

72. Which of the following lasers is used for ceramic materials in LBM?

Correct : C. pulsed co2 & nd-yag

73. Which of the following is not an advantage of LBM?

Correct : C. high equipment cost

74. Which of the following systems is used for locating the hole accurately for alignment?

Correct : B. optical laser system

75. Very                      holes with a                  aspect ratio can be produced using Laser beam machining.

Correct : B. small, large

76. How are the machining times in Laser beam machining?

Correct : D. fast machining times

77. How is the operating cost of the machines used in Laser beam machining?

Correct : A. low

78. How much amount of tapers are occurred in Laser drilled holes?

Correct : C. some amount

79. State whether the following statement regarding Laser beam machining is true or false. “In LBM, a blind hole of precise depth is easy to achieve.”

Correct : B. false

80. What is the maximum depth up to which holes can be drilled using LBM?

Correct : C. 50 mm

81. What is to be done to the adherent material which are found at exit holes?

Correct : C. remove them

82. What is the full form of PBM in the advanced machining processes?

Correct : B. plasma beam machining

83. PBM is the only process which works faster in                  steel than                    steel.

Correct : A. stainless, mild

84. What is the value of velocity of plasma jet in Plasma beam machining?

Correct : D. 500 m/sec

85. What is the value of material removal rate in Plasma Beam Machining process?

Correct : C. 150 cm3/min

86. What is the value of specific energy used in Plasma beam machining process?

Correct : A. 100 w/(cm3-min)

87. What is the value of the current used in PBM process?

Correct : C. up to 600 a

88. What is the maximum value of the thickness used in PBM process?

Correct : B. 200 mm

89. Which of the following are the different shielded plasmas used in PBM?

Correct : C. gas-shielded & water-shielded plasma

90. Material removal rates depend on which of the following factors?

Correct : D. all of the mentioned

91. A low power factors indicates                      energy required and                      removal rates.

Correct : B. low, high

92. What happens to the machining speed if the thickness of material is increased in PBM?

Correct : A. decreases

93. What is the machining speed required for machining of 12mm thick plate with 220 kW energy?

Correct : D. 2500mm/min

94. The cut edge of the material tends to be                      than the base metal in PBM.

Correct : B. harder

95. How much thickness of cracks may arise beyond HAZ due to rapid cooling?

Correct : A. 1.6 mm

96. What are the values of tolerances obtained by using PBM?

Correct : B. ± 1.6 mm

97. What is the maximum thickness of the walls of tube machined using plasma arc?

Correct : C. 50 mm

98. Which of the following are the advantages of PBM?

Correct : D. all of the mentioned

99. Which of the following chemicals are used in PBM?

Correct : D. none of the mentioned

100. How much amount of energy is required for machining using PBM?

Correct : A. low