1. A wound rotor induction motor is preferred over squirrel cage induction motor when the major consideration involved is
Correct : D. all of the above.
2. When smooth and precise speed control over a wide range is desired, the motor
preferred is
Correct : D. dc motor.
3. When quick speed reversal is a consideration, the motor preferred is
Correct : D. dc motor.
4. Stator voltage control for speed control of induction motors is suitable for
Correct : A. fan and pump drives
5. The selection of control gear for a particular application is based on the consideration of
Correct : D. all of the above.
6. As compared to squirrel cage induction motor, a wound rotor induction motor is
preferred when the major consideration is
Correct : A. high starting torque
7. A synchronous motor is found to be more economical when the load is above
Correct : D. 100kW.
8. The advantage of a synchronous motor in addition to its constant speed is
Correct : A. high power factor
9. In motor circuit static frequency changers are used for
Correct : D. speed regulation.
10. In case of traveling cranes, the motor preferred for boom hoist is
Correct : A. AC slip ring motor
11. The characteristics of drive for. crane hoisting and lowering is
Correct : D. all of the above.
12. The capacity of a crane is expressed in terms of
Correct : C. Tonnes
13. The traveling speed of cranes varies from
Correct : A. 1 to 2.5 m/s
14. In overhead traveling cranes
Correct : C. short time rated motors arc preferred
15. 15 minute rated motors are suitable for
Correct : A. light duty cranes
16. Light duty cranes are generally used in
Correct : D. All of the above.
17. Heavy duty cranes are used in
Correct : D. All of the above.
18. 1/2 hour rated motors are used for
Correct : B. medium duty cranes
19. Which of the following drive can be used for derricks and winches ?
Correct : D. Any of the above.
20. The number of sets used in pole changing type squirrel cage motors for derricks and winches, is
Correct : B. 3
21. A pole changing type squirrel cage motor used in derricks has four, eight and twenty four poles. In this the medium speed is used for
Correct : A. lifting
22. A pole changing type squirrel cage motor used in derricks has four, eight and
twenty four poles. In this the lowest speed is used for
Correct : D. landing the load.
23. For handing fragile articles in a crane
Correct : A. low speed is preferred
24. The range of horse power of electric motor drives for rolling mills is of the order of
Correct : D. 100 to 500 HP.
25. Motors preferred for rolling mill drive is
Correct : C. any of the above
26. The .......motors, because of their inherent characteristics, are best suited for the rolling mills
Correct : A. dc motors
27. In case of kiln drives
Correct : C. starting torque is more than double of the running torque.
28. Motor preferred for kiln drives is usually
Correct : D. any of the above.
29. Belt conveyors offer
Correct : D. high starting torque.
30. In case belt conveyors
Correct : A. squirrel cage motors with direct-on-line starters are used
31. Which of the following motor is preferred for blowers ?
Correct : B. squirrel cage induction motor
32. Centrifugal pumps are usually driven by
Correct : C. squirrel cage induction motors
33. In case of centrifugal pumps the starting torque is generally
Correct : D. less than running torque.
34. In a centrifugal pump if the liquid to be pumped has density twice that of water, then the horse power required
(as compared to that while pumping water) will be
Correct : C. double
35. Wound rotor and squirrel-cage motors with high slip which develop maximum
torque at stand still are used for
Correct : B. presses and punches
36. Belted slip ring induction motor is almost invariably used for
Correct : B. jaw crushers
37. A solar cell converts light energy into __________
Correct : A. Electrical energy
38. There are three types of the solar cells.
Correct : A. True
39. The output power of the centrifugal pump is proportional to the _________ of the speed.
Correct : B. Cube
40. There are four types of Water pumps.
Correct : B. False
41. The output of the Solar panel is DC.
Correct : A. True
42. Which of the relationship is correct in Permanent magnet DC motor?
Correct : C. T ∝ Ia
43. Which of the relationship is correct in Permanent magnet DC motor?
Correct : C. E ∝ N
44. Who made the first solar cell?
Correct : A. Gerald Pearson
45. When was the first solar cell invented?
Correct : B. 1954
46. Which of the following is an advantage of electric traction over other methods of
traction ?
Correct : A. Faster acceleration
47. Which of the following is the voltage for single phase A.C. system ?
Correct : A. 22 V
48. Long distance railways use which of the following ?
Correct : B. 25 kV single phase A.C.
49. The speed of a locomotive is controlled by
Correct : D. regulating steam flow to engine
50. Main traction systems used in India are, those using
Correct : D. all of the above
51. For diesel locomotives the range of horsepower is
Correct : C. 1500 to 2500
52. _______ locomotive has the highest operational availability.
Correct : A. Electric
53. The horsepower of steam locomotives is
Correct : A. upto 1500
54. The overall efficiency of steam locomotive is around
Correct : A. 5 to 10 percent
55. In tramways which of the following motors is used ?
Correct : B. D.C. series motor
56. In a steam locomotive electric power is provided through
Correct : C. small turbo-generator
57. Which of the following drives is suitable for mines where explosive gas exists ?
Correct : C. Battery locomotive
58. Overload capacity of diesel engines is usually restricted to
Correct : A. 2 percent
59. The wheels of a train, engine as well as bogies, are slightly tapered to
Correct : D. facilitate in taking turns
60. The efficiency of diesel locomotives is nearly
Correct : A. 20 to 25 percent
61. Which of the following is the advantage of electric braking ?
Correct : A. It avoids wear of track
62. Which of the following braking systems on the locomotives is costly ?
Correct : A. Regenerative braking on electric locomotives
63. Tractive effort is required to
Correct : D. do all of the above
64. For given maximum axle load tractive efforts of AC. locomotive will be
Correct : B. more than that of D.C. locomotive
65. Due to which of the following co-efficient of adhesion improves ?
Correct : D. All of the above
66. Which of the following is the disadvantage of electric traction over other systems of
traction ?
Correct : C. High capital outlay in fixed instal-lations beside route limitation
67. Speed-time curve of main line service differs from those of urban and suburban
services on following account
Correct : D. all of the above
68. The rate of acceleration on suburban orurban services is restricted by the
consideration of
Correct : D. Track size
69. The specific energy consumption of a train depends on which of the following ?
Correct : C. Distance covered
70. The friction at the track is proportional to
Correct : C. speed
71. The resistance encountered by a train in motion is on account of
Correct : D. all of the above
72. Battery operated trucks are used in
Correct : D. factories for material transportation
73. method can bring the locomotive to dead stop.
Correct : A. Plugging braking
74. The voltage used for suburban trains in D.C. system is usually
Correct : D. 600 to 750 V
75. For three-phase induction motors which of the following is the least efficient method of speed control ?
Correct : C. Rheostatic control
76. Specific energy consumption becomes
Correct : D. all of the above
77. In main line service as compared to urban and suburban service
Correct : D. all of the above
78. Locomotive having monomotor bogies
Correct : D. has all above qualities
79. Series motor is not suited for traction duty due to which of the following account ?
Correct : B. Current surges after temporary switching off supply
80. When a bogie negotiates a curve, reduction in adhesion occurs resulting in sliding.
Thus sliding is acute when
Correct : C. both (A) and (B)
81. Energy consumption in propelling the train is required for which of the following?
Correct : D. All of the above
82. An ideal traction system should have
Correct : D. all of the above
83. have maximum unbalanced forces
Correct : B. Steam locomotives
84. Specific energy consumption is affected by which of the following factors ?
Correct : D. All of the above
85. In case of ________ free running and coasting periods are generally long.
Correct : A. main-line service
86. Overhead lines for power supply to tramcars are at a minimum height of
Correct : C. 10 m
87. The return circuit for tramcars is through
Correct : B. rails
88. _______ frequency is not common in low frequency traction system
Correct : A. 40 Hz
89. For 25 kV single phase system power supply frequency is
Correct : B. 50 Hz
90. Power for lighting in passanger coach, in a long distance electric train, is provided
Correct : B. through individual generator of bogie and batteries
91. In India, electrification of railway track was done for the first time in which of the
following years ?
Correct : C. 1925—1932
92. Which of the following happens in Kando system ?
Correct : C. is converted into
93. For which of the following locomotives the maintenance requirements are the
least?
Correct : B. Diesel locomotives
94. Which of the following methods is used to control speed of 25 kV, 50 Hz single
phase traction ?
Correct : B. Tap changing control of transformer
95. The most suitable servo-motor application is __________