1. Electrolysis occur when which of the following takes place between electrodes?
Correct : C. all of the mentioned
2. The system which consists of electrolytic solution and electrodes can be referred to as
Correct : A. electrolytic cell
3. The chemical reactions occurring at electrodes are called with, which of the following names?
Correct : C. all of the mentioned
4. Amount of mass dissolved is directly proportional to which of the following quantities?
Correct : A. amount of electricity
5. Chemical equivalent is the ratio of which of the following factors?
Correct : B. atomic weight to work piece valence
6. What are the values of voltages used in ECM?
Correct : B. 10 to 30 v
7. How does the current pass between the two electrodes in ECM?
Correct : A. electrolytic solution
8. What is the value of velocity with which, electrolyte flows in the inter electrode gap?
Correct : C. >5 m/s
9. Of the following, electrolyte removes which of the dissolution products?
Correct : D. all of the mentioned view answer
10. State whether the following statement is true or false regarding the theory of ECM. “Application of P.D (potential difference) lead to occurrence of several reactions.”
Correct : A. true
11. Which of the following reactions takes place at the electrodes?
Correct : D. all of the mentioned
12. Which of the following reaction takes place at anode?
Correct : B. dissolution of iron
13. Which of the following reactions take place at cathode?
Correct : A. generation of hydrogen
14. Positively charged particles (cations) move towards which electrode?
Correct : B. cathode
15. Negatively charged particles (anions) move towards which electrode?
Correct : A. anode
16. Which of the following come under the main components of ECM?
Correct : D. all of the mentioned
17. Feed control system is responsible for which action in ECM?
Correct : A. giving feed to tool
18. In ECM equipment, what is the role of electrolyte supply system?
Correct : B. electrolyte supply
19. What is the role of power supply unit in ECM equipment?
Correct : C. power supply
20. For large size machining, which type of facilities are used in ECM?
Correct : C. automated & semi-automated facilities
21. Electrolyte supply system should concentrate on which of the following factors?
Correct : D. all of the mentioned
22. For high strength or rigidity, which type of coatings are recommended for metals?
Correct : B. non-metallic coatings
23. What is the value of voltage that the power supply unit supplies for ECM?
Correct : B. 2 to 30 v
24. What are the values of current densities used in ECM?
Correct : B. 5 to 500 a/cm2
25. Which type of adjustment is to be done for gap voltages?
Correct : A. continuous adjustment
26. Compared to the tool used in ECM, how should be the work piece size?
Correct : A. greater than
27. Which of the following factors are used to determine the tool geometry?
Correct : D. all of the mentioned
28. Which of the following are the simplest methods for applying the insulation on tools?
Correct : C. all of the mentioned
29. What are the main functions of electrolyte in Electrochemical machining?
Correct : D. all of the mentioned
30. Electrolytic solution should ensure which type of anodic dissolution?
Correct : A. uniform
31. State whether the following statement is true or false regarding the electrolytic solution. “In ECM, formation of passive film is recommended.”
Correct : B. false
32. Which type of electrical conductivity is necessary for electrolytic solution?
Correct : C. high
33. What are the other features of electrolytic solution in ECM?
Correct : D. all of the mentioned
34. How much should be the electrolytic solution?
Correct : B. inexpensive
35. Which are the most common electrolytes used in Electrochemical machining?
Correct : D. all of the mentioned
36. Selection of electrolyte does not depend on which of the following factors?
Correct : C. heat affected zones
37. What must be the value of electrolytic temperature in ECM?
Correct : B. 22 to 45oc
38. What must be the value of the pressure of electrolytic solution used in ECM?
Correct : C. 100 to 200 kpa
39. What must be the value of velocity of the electrolytic solution?
Correct : B. 25 to 50 m/s
40. Local metal removal rates are high at which gap locations mentioned below?
Correct : A. small gap
41. When local metal removal rates are high, how will be the current density and current efficiency?
Correct : A. high
42. Current efficiency depends on which of the following in ECM?
Correct : C. anodic material & electrolyte
43. In the following ratios of metal dissolved amounts, which one represent the current efficiency?
Correct : A. observed to theoretical
44. Apparent current efficiency is due to which of the following factors?
Correct : D. all of the mentioned
45. State whether the following statement is true or false regarding the working principles. “In ECM, grain boundary attacks remove the grains through electrolytic forces.”
Correct : A. true
46. In ECM, gap increase proportional to which relation of time below?
Correct : B. square root of time
47. At constant feed rates what happens to gap thickness?
Correct : C. becomes constant
48. At constant gap thickness material removal becomes equal to feed rate. What is this gap called?
Correct : B. equilibrium gap
49. If the gap thickness is greater than equilibrium thickness what will be MRR?
Correct : A. mrr is less than feed rate
50. During ECM drilling, decrease in feed rates lead to which type of machining gaps?
Correct : A. wider
51. Too small gap causes which of the following effects?
Correct : C. sparking & short circuit
52. Electro chemical dissolution phase starts with the movement of ions between which two components?
Correct : A. cathode and anode
53. Better surface finish and higher accuracy depend on which of the factors below?
Correct : C. all of the mentioned
54. For alloys, which type of electrolyte is used in ECM?
Correct : C. multi component
55. Nickel can be machined with 100% current efficiency, when current density value is
Correct : B. 25 a/cm2
56. When the electrolyte flow is low, what happens to the current efficiency?
Correct : B. decreases
57. When machining Ti, in Nacl electrolyte, what values of current efficiencies are obtained?
Correct : A. 10 – 20 %
58. State whether the following statement is true or false about electrolyte in ECM. “Machinability in ECM is enhanced, when electrolyte is heated.”
Correct : A. true
59. What must be the working voltage in Electrochemical machining?
Correct : B. 20 v
60. Surface roughness depend on which of the following quantities?
Correct : D. all of the mentioned
61. For a better surface finish, which type of current distribution is required?
Correct : A. even
62. Between which values does the side gap’s surface roughness vary?
Correct : C. >5 µm
63. In Electrochemical machining, larger grain size causes which type of finish?
Correct : B. rougher
64. Which type of gap width is necessary for a higher degree of accuracy?
Correct : B. small
65. Accuracy of machining is affected by, which of the following factors?
Correct : D. all of the mentioned
66. Which properties of electrolyte does not affect the accuracy of the process?
Correct : C. non-reactive
67. For high process accuracy, which of the following factors are needed?
Correct : C. high feed rate & high conductivity
68. Tool insulation that the side machining action is needed in the process of ECM.
Correct : A. limits
69. If the current density is high as required, what type of machining occurs?
Correct : B. polishing
70. What happens when the current density is low in ECM?
Correct : C. pitting & etching occurs
71. Fine dimensional control can be obtained if throwing power of electrolyte is
Correct : A. low
72. Passivation is done on electrolytes in order to form which of the following?
Correct : A. passive layer on machined parts
73. If there is an increase in the electrolyte flow, what happens to the rate of film formation?
Correct : B. decreases
74. It is difficult to machine inner radii smaller than and outer radii less than
Correct : C. 0.8 mm, 0.5 mm
75. What is the value of the overcut that is obtained using ECM?
Correct : B. 0.5 mm
76. If there is a change in the selected machining conditions, it will have impact on which of the following?
Correct : C. process accuracy & surface finish
77. Surface roughness depends on current density, which is affected by which of the following?
Correct : D. all of the mentioned
78. Machining conditions leading to high accuracy are associated with surface roughness and productivity.
Correct : B. smaller, greater
79. Non stationary behaviour of ECM is due to, which of the factors below?
Correct : D. all of the mentioned
80. For large components, actual machining time constitutes to how much percentage of the total machining time?
Correct : D. high
81. What happens to the product cycle time, if the machining performance is improved?
Correct : B. decreases
82. The cost of additional control hardware remain a fraction of total machining cost.
Correct : A. small
83. With an increase in unmanned machining hours, what happens to the efficiency of ECM?
Correct : A. increases
84. Which type of damage is caused by deterioration which is caused by spark?
Correct : B. irreparable
85. Which of the following use ECM for different applications?
Correct : D. all of the mentioned
86. Which of the following processes can be done using ECM?
Correct : D. all of the mentioned
87. Which of the following material cannot be machined using ECM?
Correct : C. nonconductive materials
88. ECM is used to the sharp edges produced after rough cuts.
Correct : B. dull
89. ECM is usually characterized as low accuracy machining, for which of the following reason?
Correct : B. wider gap width
90. In micro ECM, which of the following is used as micro tool?
Correct : A. electrolyte jet
91. Micro ECM is used to machine which type of parts?
Correct : B. micro parts
92. Which of the following produces small indents and cavities using micro ECM?
Correct : C. moving the work piece & switching the pulse current
93. What fraction of tool will always be in contact with the work piece?
Correct : C. no contact
94. How much amount of wear is present in the tool used in Electrochemical machining?
Correct : A. no wear
95. Compared to other processes, machining is done at voltages for high rates of material removal.
Correct : C. high
96. Very small dimensions, up to which value can be controlled using ECM?
Correct : B. 0.05 mm
97. Complicated profiles can be machined in how many operations in Electrochemical machining?
Correct : A. single
98. How much amount of thermal damage occurs to the work piece?
Correct : C. no thermal damage
99. Which of the following materials can be machined using ECM?
Correct : B. hard conductive materials
100. What are the requirements of labour for machining purpose in Electrochemical machining?