1. Which of the following component is usually fabricated out of silicon steel ?
2. The frame of an induction motor is usually made of ______.
3. The shaft of an induction motor is made of ______.
5. In an induction motor, no-load the slip is generally ______.
6. In medium sized induction motors, the slip is generally around ______.
7. In squirrel cage induction motors, the rotor slots are usually given slight skew in order to
8. In case the air gap in an induction motor is increased ______.
9. Slip rings are usually made of _______.
10. A 3-phase 440 V, 50 Hz induction motor has 4% slip. The frequency of rotor e.m.f. will be
11. In Ns is the synchronous speed and s the slip, then actual running speed of an induction motor will be
12. The efficiency of an induction motor can be expected to be nearly
13. The number of slip rings on a squirrel cage induction motor is usually
14. The starting torque of a squirrel-cage induction motor is
15. A double squirrel-cage induction motor has
16. Star-delta starting of motors is not possible in case of
17. The term 'cogging' is associated with _______.
18. In case of the induction motors the torque is _______.
19. An induction motor with 1000 r.p.m. speed will have
20. The good power factor of an induction motor can be achieved if the average flux density in the air gap is
21. An induction motor is identical to ________.
22. The injected e.m.f. in the rotor of induction motor must have
23. Which of the following methods is easily applicable to control the speed of the squirrel-cage induction motor ?
24. The crawling in the induction motor is caused by ______.
25. The auto-starters (using three auto transformers) can be used to start cage induction motor of the following type
26. The torque developed in the cage induction motor with autostarter is
27. When the equivalent circuit diagram of double squirrel-cage induction motor is constructed the two cages can be considered
28. It is advisable to avoid line-starting of induction motor and use starter because
29. Stepless speed control of induction motor is possible by which of the following methods ?
30. Rotor rheostat control method of speed control is used for
31. In the circle diagram for induction motor, the diameter of the circle represents
32. For which motor the speed can be controlled from rotor side ?
33. If any two phases for an induction motor are interchanged
34. An induction motor is ______.
35. The maximum torque in an induction motor depends on ______.
36. In three-phase squirrel-cage induction motors ______.
37. In a three-phase induction motor, the number of poles in the rotor winding is always
38. DOL starting of induction motors is usually restricted to
39. The speed of a squirrel-cage induction motor can be controlled by all of the following except
40. The 'crawling" in an induction motor is caused by ______.
41. The power factor of an induction motor under no-load conditions will be closer to
42. The 'cogging' of an induction motor can be avoided by
43. If an induction motor with certain ratio of rotor to stator slots, runs at 1/7 of the normal speed, the phenomenon will be termed as
44. Slip of an induction motor is negative when
45. Size of a high speed motor as compared to low speed motor for the same H.P. will be
46. A 3-phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Then the motor
47. A 3-phase induction motor delta connected is carrying too heavy load and one of its fuses blows out. Then the motor
48. Low voltage at motor terminals is due to ______.
49. In an induction motor the relationship between stator slots and rotor slots is that
50. Slip ring motor is recommended where ______.
51. As load on an induction motor goes on increasing ______.
52. If a 3-phase supply is given to the stator and rotor is short circuited rotor will move
53. It is advisable to avoid line starting of induction motor and use starter because
54. The speed characteristics of an induction motor closely resemble the speedload characteristics of which of the following machines
55. Which type of bearing is provided in small induction motors to support the rotor shaft ?
56. A pump induction motor is switched on to a supply 30% lower than its rated voltage. The pump runs. What will eventually happen ? It will
57. 5 H.P., 50-Hz, 3-phase, 440 V, induction motors are available for the following r.p.m. Which motor will be the costliest ?
58. A 3-phase slip ring motor has _____.
59. The starting torque of a 3-phase squirrel cage induction motor is
60. Short-circuit test on an induction motor cannot be used to determine
61. In a three-phase induction motor is _______.
62. In case of 3-phase induction motors, plugging means _______.
63. Which is of the following data is required to draw the circle diagram for an induction motor ?.
64. In three-phase induction motors sometimes copper bars are placed deep in the rotor to
65. In a three-phase induction motor is ______.
66. The value of transformation ratio of an induction motor can be found by
67. The power scale of circle diagram of an induction motor can be found from
68. The shape of the torque/slip curve of induction motor is
69. A change of 4% of supply voltage to an induction motor will produce a change of approximately
70. The stating torque of the slip ring induction motor can be increased by adding
71. A 500 kW, 3-phase, 440 volts, 50 Hz, A.C. induction motor has a speed of 960 r.p.m. on full load. The machine has 6 poles. The slip of the machine will be
72. The complete circle diagram of induetion motor can be drawn with the help of data found from
73. In the squirrel-cage induction motor the rotor slots are usually given slight skew
74. The torque of a rotor in an induction motor under running condition is maximum
75. What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero ?
76. The circle diagram for an induction motor cannot be used to determine
77. Blocked rotor test on induction motors is used to find out
78. Lubricant used for ball bearing is usually _______.
79. An induction motor can run at synchronous speed when
80. Which motor is preferred for use in mines where explosive gases exist ?
81. The torque developed by a 3-phase induction motor least depends on
82. In an induction motor if air-gap is increased
83. In induction motor, percentage slip depends on
84. When R2 is the rotor resistance, X2 the rotor resistance at supply frequency and s the slip, then the condition for maximum torque under running conditions will be
85. In case of a double cage induction motor, the inner cage has
86. The low power factor of induction motor is due to ______.
87. Insertion of reactance in the rotor circuit ______.
88. Insertion of resistance in the rotor of an induction motor to develop a given torque
89. For driving high inertia loods best type of induction motor suggested is
90. Temperature of the stator winding of a three phase induction motor is obtained by
91. The purpose of using short-circuit gear is ________.
92. In a squirrel cage motor the induced e.m.f. is ______.
93. Less maintenance troubles are experienced in case of ______.
94. A squirrel cage induction motor is not selected when ______.
95. Reduced voltage starter can be used with _______.
96. Slip ring motor is preferred over squirrel cage induction motor where ______.
97. In a star-delta starter of an induction motor ______.
98. The torque of an induction motor is ______.
99. The rotor of an induction motor runs at _______.
100. The starting torque of a three phase induction motor can be increased by ______.
101. Insertion of resistance in the stator of an induction motor _______.
2. The frame of an induction motor is usually made of ______.
3. The shaft of an induction motor is made of ______.
5. In an induction motor, no-load the slip is generally ______.
6. In medium sized induction motors, the slip is generally around ______.
7. In squirrel cage induction motors, the rotor slots are usually given slight skew in order to
8. In case the air gap in an induction motor is increased ______.
9. Slip rings are usually made of _______.
10. A 3-phase 440 V, 50 Hz induction motor has 4% slip. The frequency of rotor e.m.f. will be
11. In Ns is the synchronous speed and s the slip, then actual running speed of an induction motor will be
12. The efficiency of an induction motor can be expected to be nearly
13. The number of slip rings on a squirrel cage induction motor is usually
14. The starting torque of a squirrel-cage induction motor is
15. A double squirrel-cage induction motor has
16. Star-delta starting of motors is not possible in case of
17. The term 'cogging' is associated with _______.
18. In case of the induction motors the torque is _______.
19. An induction motor with 1000 r.p.m. speed will have
20. The good power factor of an induction motor can be achieved if the average flux density in the air gap is
21. An induction motor is identical to ________.
22. The injected e.m.f. in the rotor of induction motor must have
23. Which of the following methods is easily applicable to control the speed of the squirrel-cage induction motor ?
24. The crawling in the induction motor is caused by ______.
25. The auto-starters (using three auto transformers) can be used to start cage induction motor of the following type
26. The torque developed in the cage induction motor with autostarter is
27. When the equivalent circuit diagram of double squirrel-cage induction motor is constructed the two cages can be considered
28. It is advisable to avoid line-starting of induction motor and use starter because
29. Stepless speed control of induction motor is possible by which of the following methods ?
30. Rotor rheostat control method of speed control is used for
31. In the circle diagram for induction motor, the diameter of the circle represents
32. For which motor the speed can be controlled from rotor side ?
33. If any two phases for an induction motor are interchanged
34. An induction motor is ______.
35. The maximum torque in an induction motor depends on ______.
36. In three-phase squirrel-cage induction motors ______.
37. In a three-phase induction motor, the number of poles in the rotor winding is always
38. DOL starting of induction motors is usually restricted to
39. The speed of a squirrel-cage induction motor can be controlled by all of the following except
40. The 'crawling" in an induction motor is caused by ______.
41. The power factor of an induction motor under no-load conditions will be closer to
42. The 'cogging' of an induction motor can be avoided by
43. If an induction motor with certain ratio of rotor to stator slots, runs at 1/7 of the normal speed, the phenomenon will be termed as
44. Slip of an induction motor is negative when
45. Size of a high speed motor as compared to low speed motor for the same H.P. will be
46. A 3-phase induction motor stator delta connected, is carrying full load and one of its fuses blows out. Then the motor
47. A 3-phase induction motor delta connected is carrying too heavy load and one of its fuses blows out. Then the motor
48. Low voltage at motor terminals is due to ______.
49. In an induction motor the relationship between stator slots and rotor slots is that
50. Slip ring motor is recommended where ______.
51. As load on an induction motor goes on increasing ______.
52. If a 3-phase supply is given to the stator and rotor is short circuited rotor will move
53. It is advisable to avoid line starting of induction motor and use starter because
54. The speed characteristics of an induction motor closely resemble the speedload characteristics of which of the following machines
55. Which type of bearing is provided in small induction motors to support the rotor shaft ?
56. A pump induction motor is switched on to a supply 30% lower than its rated voltage. The pump runs. What will eventually happen ? It will
57. 5 H.P., 50-Hz, 3-phase, 440 V, induction motors are available for the following r.p.m. Which motor will be the costliest ?
58. A 3-phase slip ring motor has _____.
59. The starting torque of a 3-phase squirrel cage induction motor is
60. Short-circuit test on an induction motor cannot be used to determine
61. In a three-phase induction motor is _______.
62. In case of 3-phase induction motors, plugging means _______.
63. Which is of the following data is required to draw the circle diagram for an induction motor ?.
64. In three-phase induction motors sometimes copper bars are placed deep in the rotor to
65. In a three-phase induction motor is ______.
66. The value of transformation ratio of an induction motor can be found by
67. The power scale of circle diagram of an induction motor can be found from
68. The shape of the torque/slip curve of induction motor is
69. A change of 4% of supply voltage to an induction motor will produce a change of approximately
70. The stating torque of the slip ring induction motor can be increased by adding
71. A 500 kW, 3-phase, 440 volts, 50 Hz, A.C. induction motor has a speed of 960 r.p.m. on full load. The machine has 6 poles. The slip of the machine will be
72. The complete circle diagram of induetion motor can be drawn with the help of data found from
73. In the squirrel-cage induction motor the rotor slots are usually given slight skew
74. The torque of a rotor in an induction motor under running condition is maximum
75. What will happen if the relative speed between the rotating flux of stator and rotor of the induction motor is zero ?
76. The circle diagram for an induction motor cannot be used to determine
77. Blocked rotor test on induction motors is used to find out
78. Lubricant used for ball bearing is usually _______.
79. An induction motor can run at synchronous speed when
80. Which motor is preferred for use in mines where explosive gases exist ?
81. The torque developed by a 3-phase induction motor least depends on
82. In an induction motor if air-gap is increased
83. In induction motor, percentage slip depends on
84. When R2 is the rotor resistance, X2 the rotor resistance at supply frequency and s the slip, then the condition for maximum torque under running conditions will be
85. In case of a double cage induction motor, the inner cage has
86. The low power factor of induction motor is due to ______.
87. Insertion of reactance in the rotor circuit ______.
88. Insertion of resistance in the rotor of an induction motor to develop a given torque
89. For driving high inertia loods best type of induction motor suggested is
90. Temperature of the stator winding of a three phase induction motor is obtained by
91. The purpose of using short-circuit gear is ________.
92. In a squirrel cage motor the induced e.m.f. is ______.
93. Less maintenance troubles are experienced in case of ______.
94. A squirrel cage induction motor is not selected when ______.
95. Reduced voltage starter can be used with _______.
96. Slip ring motor is preferred over squirrel cage induction motor where ______.
97. In a star-delta starter of an induction motor ______.
98. The torque of an induction motor is ______.
99. The rotor of an induction motor runs at _______.
100. The starting torque of a three phase induction motor can be increased by ______.
101. Insertion of resistance in the stator of an induction motor _______.
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