1. In Electro discharge machining, materials with low melting point have which type of material removal rate?
Correct : D. high
2. In Electro discharge machining, materials with low melting point have which type of surface roughness?
Correct : A. rough
3. What happens to the material removal rate if the sparks are very less in EDM?
Correct : A. decreases
4. What is the relation between the melting point and the material removal rate?
Correct : B. inversely proportional
5. What happens to the crater size if we increase the current keeping the pulse time constant?
Correct : A. increase
6. What happens to the crater size if we decrease the pulse time keeping the current constant?
Correct : B. decrease
7. On which of the following factors do the craters depend?
Correct : D. all of the mentioned
8. The maximum depth of damaged layer is how many times that of average surface roughness?
Correct : C. 2.5 times
9. What happens to the surface roughness values if the MRR increases in EDM?
Correct : A. increases
10. In Electro discharge machining, what happens to the surface finish if the pulse energy is decreased?
Correct : C. improves
11. Using of a mate electrode in Electro discharge machining the surface roughness of material.
Correct : B. decreases
12. What happens to the surface roughness if oxygen gas is introduced in the gap?
Correct : B. decreases
13. What are the tolerance values obtained by machining using EDM?
Correct : C. ± 25 mm
14. How much extra tolerances are achieved when we choose proper variables?
Correct : A. ± 5 mm
15. What is the value of thickness of recast layer obtained when power of 5 µJ is given?
Correct : A. 1 µm
16. The depth of the annealed surface is to the amount of power used in machining operation.
Correct : A. directly proportional
17. In EDM, choosing electrodes that produce which type of machining reduces the annealing effect?
Correct : A. stable
18. What happens to the fatigue strength of alloys if altered surfaces are produced in Electro discharge machining?
Correct : B. reduces
19. The altered layers formed during the process of EDM consists of which of the following?
Correct : D. all of the mentioned
20. During roughing process through Electro discharge machining, what is the thickness of layer formed?
Correct : B. <0.125 mm
21. During finishing process through Electro discharge machining, what is the value thickness of layer formed?
Correct : A. <0.075 mm
22. Which of the following processes can be used for restoration of fatigue properties?
Correct : D. all of the mentioned
23. State whether the following statement is true or false regarding the HAZ in EDM. “In EDM, post treatment to recover fatigue strength is not recommended.”
Correct : B. false
24. Which of the following shapes can be produced using Electro discharge machining?
Correct : C. all of the mentioned
25. Which of the following materials can be machined using Electro discharge machining?
Correct : D. all of the mentioned
26. Which of the following are the applications of Electro discharge machining?
Correct : D. all of the mentioned
27. Which type of electrode is used for drilling in Electro discharge machining?
Correct : C. tubular electrode
28. The dielectric fluid is flushed in thorough which part of the electrode in drilling in EDM?
Correct : A. interior hole
29. Which type of holes can be produced through drilling using Electro discharge machining?
Correct : D. all of the mentioned
30. What are the values of general feed rates used for drilling in EDM?
Correct : A. 0.1 mm/min
31. 10 to 0.50 mm.
Correct : A. 0.01 to 0.05 mm
32. Electro discharge sawing is an application of EDM which employs as tool material.
Correct : C. steel band & disc
33. When compared to the conventional abrasive sawing, how many times faster is the MRR?
Correct : A. twice
34. How much amount of burr is produce while machined using Electro discharge sawing?
Correct : D. no burr
35. 3 to 10 µm when machined using Electro discharge sawing.
Correct : B. 0.025 to 0.130 mm
36. Which of the following electrodes are used for machining spherical surfaces in Electro discharge machining?
Correct : A. tubular electrodes
37. What are the values of dimensional accuracy obtained while machining spherical surfaces?
Correct : A. ± 1 µm
38. What are the surface roughness values obtained while machining spherical surfaces using Electro discharge machining?
Correct : A. <0.1 µm
39. Which motion of tool is used for machining spherical surfaces in Electro discharge machining?
Correct : C. rotary
40. Which type of electrodes are used for milling application in Electro discharge machining process?
Correct : B. cylindrical type electrodes
41. Which type of cavities can be machined using milling process by Electro discharge machining?
Correct : C. simple & complex cavities
42. The simple electrodes are rotated at which speed for milling of work pieces in Electro discharge machining?
Correct : D. high
43. What happens to the dielectric flushing while milling tool is rotated at a high speed in EDM?
Correct : A. improved
44. Which of the following are the steps included in the die sinking process of EDM?
Correct : D. all of the mentioned
45. Which path of the components in wire EDM determines the path to be machined?
Correct : A. horizontal worktable movement
46. Which of the following materials are machined using Wire Electro discharge machining?
Correct : D. all of the mentioned
47. How much amount of burr is produce when we use Wire Electro discharge machining for machining of work pieces?
Correct : C. no burr
48. Which of the following industries use wire EDM for different applications?
Correct : D. all of the mentioned
49. While machining insulating ceramic materials using EDM, where is the sheet metal placed?
Correct : A. over material
50. Sparks occur between which of the following components?
Correct : B. tool electrode and sheet metal
51. Texturing is applied to the steel sheets at which stages of cold rolling?
Correct : A. initial stages
52. What is the full form of EDT in EDM processes?
Correct : B. electro discharge texturing
53. Which of the following are the process variables for texturing process in EDM?
Correct : D. all of the mentioned
54. What are the values of current amplitudes used in EDT?
Correct : B. 2 to 10 a
55. What are duration values of current amplitude in EDT?
Correct : C. 10 to 100 µs
56. What are the spindle rotation speeds used in EDT?
Correct : B. 10 to 40 rpm
57. What happens to the machine capital cost in EDT when there is an increase in tool quantity?
Correct : B. increases
58. What is the value of depth to diameter ratio in Micro-Electro discharge machining process?
Correct : A. 10:1
59. What are the values of depths that can be machined using Micro-EDM?
Correct : C. 100 mm
60. What are the machining rates used in Micro-EDM process?
Correct : B. 1 to 20 mm/min
61. What are the values of hole diameters obtained using Wire electro discharge grinding?
Correct : C. 5 µm
62. What are the feed rates used in WEDG process?
Correct : B. 5 to 10 mm/min
63. Which of the following is a major difficulty in the Electro discharge machining process?
Correct : B. abnormal discharges
64. What has been done to the off time when there is a no-load voltage of electric discharge?
Correct : A. increased
65. In a simple application which of the following parameters are inputs?
Correct : A. pulse duration and current
66. In a simple application which of the following parameters are outputs?
Correct : A. pulse duration and current
67. Which of the following are correlated with the machining conditions at output stage?
Correct : D. all of the mentioned
68. How are EDM’s levels of integration when compared to conventional machining?
Correct : A. slower rate
69. Manufacturing of tool electrode undergoes which of the following processes?
Correct : D. all of the mentioned
70. High temperatures produced in the working gap results in which of the following potentials?
Correct : D. all of the mentioned
71. Hydro carbons present in the dielectric fluid have impact on which of the body parts?
Correct : C. skin
72. What happens to the Electro discharge machining process under unfavourable working conditions?
Correct : B. explosion may occur
73. Reduction in the electrical energy consumption will have impact on which aspects mentioned below?
Correct : C. environmental & economic
74. A thin metallic wire used in wire-cut EDM is kept submerged in a tank of
Correct : A. dielectric fluid
75. Wire-cut EDM can cut plates of thickness upto
Correct : C. 300mm
76. In WEDM, the wire is held tight between
Correct : B. upper and lower diamond guides
77. The upper guide can move independently about
Correct : D. z-u-v axes
78. In the wire-cut EDM process, de-ionizing units are used for controlling the
Correct : B. resistivity
79. In the wire-cut EDM process, water is also used for
Correct : C. flushing away the burr
80. The WEDM process requires
Correct : B. lesser cutting forces
81. The materials which are not stress-relieved before machining by WEDM process can get distorted during machining.
Correct : A. true
82. During the WEDM process, workpiece undergoes a number of thermal cycles.
Correct : A. true
83. Electrically conductive materials are cut by WEDM process by mechanism.
Correct : B. electro-thermal
84. In wire-cut EDM process, material removal takes place by a series of discrete discharges between
Correct : B. the wire-electrode and the workpiece
85. The di-electric fluid gets ionizes in between gap.
Correct : A. tool-electrode
86. The burr or cut particles are flushed away by the
Correct : C. di-electric fluid
87. Wire-cut EDM (WEDM) process is widely used for
Correct : B. tool steels
88. For which of the following materials wire-cut EDM is not used?
Correct : B. zirconium
89. WEDM process can be used for cutting hard extrusion dies.
Correct : A. true
90. WEDM process can be used for manufacturing of micro-tools.
Correct : A. true
91. How many subsystems are there in wire-cut EDM process?
Correct : C. 4
92. Di-electric system used in WEDM process is similar to that of the process.
Correct : C. conventional edm
93. In wire-cut EDM, a moving wire is used to
Correct : B. cut complex outlines
94. Wire electric discharge (ED) machining is based on the same principle as that of
Correct : B. die-sink edm
95. The only difference between die-sink EDM and wire cut EDM is the
Correct : B. electrode used for the machining
96. During wire cut EDM, the size of the cavity produced by the wire while machining depends upon
Correct : D. electric current
97. Sparking gap is the distance between
Correct : B. the workpiece and the electrode wire
98. The absolute minimum inner corner radius is
Correct : C. the wire radius plus the sparking gap width
99. Which of the following component of the wire cut EDM machine does not get heated?
Correct : B. electrode wire
100. Which of the following material properties sets restrictions to use wire cut EDM?