Correct : A. group of steel prone to corrosion in welding in the range of 500
to 800 oc
2. the type of corrosion which is produced by con=mbined effect of mechanical stress and a corrosive environment on metal is called as
Correct : B. stress corrosion cracking
3. in stress corrosion cracking
Correct : D. all of the above
4. the critical level of stress depends uopn
factor
Correct : D. all of the above
5. the critical level of stress depends uopn
factor
Correct : D. all of the above
6. carbon steels crack in nitrate solutions is a type of
Correct : C. intergranular corrosion
7. Cu and its alloys crack in ammonia and environments containing mercury
Correct : C. intergranular corrosion
8. for a given metal or alloy, the possibility of stress corrosion depends upon
Correct : A. the oxygen content and ph value of electrolyte
9. at a juction of two metals exposed to a corrosive environment is leads to
Correct : D. crevice corrosion
10. due to difference in oxygen concentration at two different points it leads to
Correct : D. erosion corrosion
11. the type of corrosion which take place in nut and bolt fittings is
Correct : C. crevice corrosion
12. the combined effect of abrading action of turbulent flow of gases, vapours liquids and mechanical rubbing action of solids over a
Correct : A. pitting corrosion
13. erosion corrosion caused by
Correct : C. both a and b
14. if a liquid passes from low pressure to high pressure region the type of corrosion is known as
Correct : C. cavitation corrosion
15. due to collapse of vapours on walls of pipes it leads
Correct : C. cavitation corrosion
16. cavitation corrosion can be miminized by
Correct : D. all of the above
17. small anodic area and large cathod is observed in
Correct : C. both a and b
18. rotating pumps, valves are prone to
Correct : C. both a and b
19. the components like heat exchanger are prone to
Correct : C. high temperature corrosion
20. the resistance of material to high temperature corrosion can be increased by
Correct : C. both a and b
21. combined action of corrosion and repeated cyclic loading is called as
Correct : D. corrosion fatigue
22. corrosion fatigue can be reduce by
Correct : D. all of the above
23. hydrogen embrittlement
Correct : A. it is a low temperature phenomenon
24. because of diffusion of hydrogen into the metal, the metal becomes brittle that leads to failure of the component is knowna as
Correct : A. hydrogen embrittleme nt
25. in hydrogen embrittlement if the pressure of molecular hydrogen is greate rhan the yield strength of the material
Correct : A. then the component becomes brittle
26. in hydrogen embrittlement if the pressure of molecular hydrogen is greater than the ultimate strength of the material
Correct : B. then the component will fail
27. hydrogen embrittlement
Correct : A. reduces the strength and increases the brittleness of the region around the defect
28. low temperature phenomena associated with hydrogen is known as
Correct : A. hydrogen embrittleme nt
29. HIgh temperature phenomena associated with hydrogen is known as
Correct : C. hydrogen attack
30. in case of steels, the raection between hydrogen and carbon forms methane which causes intergranular carcking, fissuring or blistering is known as
Correct : C. hydrogen attack
31. according to principles usedin control and preventaion of design, the various methods (techniques) are classified as
Correct : D. all of the above
32. the choice of metal or an alloy for any application depends on factors like
Correct : D. all of the above
33. following points are considered while selecting the material for a particular application
Correct : D. all of the above
34. metarials with characteristics have higher corrosion resistance
Correct : D. all of the above
35. during design and fabrication of the component, should be considered
Correct : D. all of the above
36. during design and fabrication of the pipe and tanks, sharp bends and corners should be avoided because they form
Correct : C. both a and b
37. during design and fabrication of component,
type of joints should be used
Correct : A. welded
38. during design and fabriaction of the component, a good design should have
properties
Correct : D. all of the above
39. in modification of corrosive environment, the corrosive nature of environment is reduced by
Correct : C. both a and b
40. modification of corrosive environment is done by technique
Correct : D. all of the above
41. in modification of corrosive environment, in oxygen concentrated cell, the technique of removel of oxygen from acqueous environmnet to reduce corrosion is called as
Correct : A. deaeration
42. in modification of corrosive environment, during technique, certain chemicals are added which combine rapildy
with oxygen in acquous solution and reduce
Correct : B. deactivation
43. chemical is added during deactivation technique to modify corrosive environment
Correct : C. both a and b
44. in modification of corrosion environment,
technique resuces the moisture content of air in such a way that moisture should not condense on the metal surface causing corrosion
Correct : C. dehumidifica tion
45. substance which absobe moisture on its surface is used in dehumidification technique for midifiaction of corrosive environment
Correct : C. both a and b
46. method of corrosive prevention is useful only in closed areas like air conditioned shops, laboratories, computer rooms etc.
Correct : B. dehumidifica tion
47. method is used to prevent the corroive environmnet by neutralising the acidic character of corrosive conditions
Correct : C. alkaline neutralizatio n
48. substance is used in alkaline neutralization to prevent corrosive effect of environment
Correct : D. all of the above
49. method of corrosion prevention has widely ued in controlling the corrosion of refinery equipments
Correct : C. alkaline neutralizatio n
50. in use of speacial alloys, alloying of with iron increase corrosion resitance
Correct : C. both a and b
51. in use of speacial alloys, alloying with increases corrosion resistance of brasses and
Correct : D. tin
52. in use of special alloys, for cast irons, addition of increases the corrosion resistance
Correct : D. all of the above
53. in corrosion prevention, the metal to be protected from corrosion is forced to behace like cathode in protection method
Correct : B. cathodic
54. is a type of cathodic protection to prevent corrosion
Correct : C. both a and b
55. in cathodic protection, the commonly used sacrificial anode is
Correct : D. all of the above
56. is the advantage of sacrificial anodic protection
Correct : D. all of the above
57. is the limitation of sacrificial anodic protection
Correct : D. all of the above
58. is the application od sacrificial anodic protection
Correct : D. all of the above
59. in , an impressed external current is applied in the opposite direction to the metal to nullify the corrosion current
Correct : A. impressed current mehtod of
cathodic
60. is the advantage of impressed current method of cathodic protection
Correct : D. all of the above
61. is the limitation of impressed current method of cathodic protection
Correct : D. all of the above
62. is the application of impressed current method of cathodic protection
Correct : D. all of the above
63. is the phenomenon in which a metal or an alloy exibits higher corrosion resistabce than expected from its position in the electrochemical series by forming protective, thin, nonporous oxide film on the surface
Correct : B. passivity
64. passivity phenomenon of anodic protection is quite common with metal like
Correct : D. all of the above
65. in protection method, the part of metal to be protected from corrosion is made anodic by passing an impressed direct current in the same direction as that of corrosion current
Correct : C. anodic protection
66. is ha davantage of anodic protection to prevent corrosion
Correct : D. all of the above
67. is the limitation of anodic protection to prevent corrosion
Correct : C. both a and b
68. the method of anodic protetion can be applied to carrying corrosives chemical to prevent corrosion
Correct : D. all of the above
69. the protective coatings applied to prevent corrosion should have the property of
Correct : D. all of the above
70. the most common non metallic coating used to prevent corrosion of metals is
Correct : D. all of the above
71. in metallic coating of metals afford galvanic protection to the steel
Correct : C. both a and b
72. is the method to apply metallic coating to prevent corrosion
Correct : D. all of the above
73. coatings are very useful for protecting undergraound tanks and pipes from corrosion
Correct : A. bituminous
74. is the most widely used material
Correct : B. paints
75. oxidizing substances like is used as anodic inhibitors for the protection of iron and steel from corrosion
Correct : D. all of the above
76. inhibitors prevent evolution of hydrogen (in case of acidic solution) and oxygen absorption (in case of neutral solution) to prevent corrosion
Correct : A. cathodic
77. are used as cathodic inhibitors to prevent corrosion of metals
Correct : C. antimony and arsenic oxides
78. corrosion is defined as -
Correct : B. the deterioration of metal
79. corrosion is defined as -
Correct : D. all of the above
80. corrosion give large impact on SHE, that is
Correct : C. safety, health and environment
81. the natural tendency of metal to revert back its original form, due to corrosion is termed as
Correct : D. corrosion cycle
82. for corrosion to takes place, there is need of
Correct : C. only anode, cathode and
83. on of following metal do not corrode
Correct : C. aluminium
84. on of following metal do not corrode
Correct : D. none of the above
85. on of following metal do not corrode
Correct : D. all of the above
86. all the metals stated below are very sensitive to corrosion
Correct : D. none of the above
87. on of the metal stated below is highly corrodent
Correct : D. all of the above
88. in electrochemical corrosion, at anode which type of chemical reaction taking
place
Correct : A. oxidation reaction
89. in electrochemical corrosion, at cathode which type of chemical reaction taking place
Correct : B. reduction reaction
90. in electrochemical corrosion, at cathode which type of chemical reaction is taking place
Correct : D. none of the above
91. in electrochemical corrosion at anode, which type of chemical reaction is taking
Correct : D. none of the above
92. which of the factor given below, influencing corrosion of steel?
Correct : D. all of the above
93. dry corrosion is taking place due to
Correct : D. when oxygen in the air reacts with metal
94. what is the nature of oxide film, formed on the ferrous metal due to reaction with atmosphere?
Correct : D. all of the above
95. what is nature of oxide film formed on the aluminium and copper metal due to reaction with atmosphere
Correct : B. non-porous
96. wet corrosion is based on which phenomenon
Correct : B. electro- chemical
97. general corrosion is also known as
Correct : A. uniform corrosion
98. the best example of general corrosion is
Correct : A. corrosion of manhole cover
99. the best and economic way of preventing general corrosion is