McqMate
| 1. |
The selection of an electric motor for any application depends on which of the following factors ? |
| A. | Electrical characteristics |
| B. | Mechanical characteristics |
| C. | Size and rating of motors |
| D. | All of the above |
| Answer» D. All of the above | |
| 2. |
For a particular application the type of electric-and control gear are determined by which of the following considerations ? |
| A. | Starting torque |
| B. | Conditions of environment |
| C. | Limitation on starting current |
| D. | All of the above |
| Answer» D. All of the above | |
| 3. |
Which ofthefollowingmotors is preferred for traction work ? |
| A. | Universal motor |
| B. | D.C. series motor |
| C. | Synchronous motor |
| D. | Three-phase induction motor |
| Answer» B. D.C. series motor | |
| 4. |
Which of the following motors always starts on load ? |
| A. | Conveyor motor |
| B. | Floor mill motor |
| C. | Fan motor |
| D. | All of the above |
| Answer» D. All of the above | |
| 5. |
is preferred for automatic drives. |
| A. | Squirrel cage induction motor |
| B. | Synchronous motors |
| C. | Ward-Leonard controlled |
| D. | C. motors |
| Answer» C. Ward-Leonard controlled | |
| 6. |
When the load is above a synchronous motor is found to be more economical. |
| A. | 2 kW |
| B. | 20 kW |
| C. | 50 kW |
| D. | 100 kW |
| Answer» D. 100 kW | |
| 7. |
The load cycle for a motor driving a power press will be |
| A. | variable load |
| B. | continuous |
| C. | continuous but periodical |
| D. | intermittent and variable load |
| Answer» D. intermittent and variable load | |
| 8. |
Light duty cranes are used in which of the following ? |
| A. | Power houses |
| B. | Pumping stations |
| C. | Automobile workshops |
| D. | All of the above |
| Answer» D. All of the above | |
| 9. |
While selecting an electric motor for a floor mill, which electrical characteristics will be of least significance ? |
| A. | Running characteristic |
| B. | Starting characteristics |
| C. | Efficiency |
| D. | Braking |
| Answer» D. Braking | |
| 10. |
Which of the following motors are pre-ferred for overhead travelling cranes ? |
| A. | Slow speed motor |
| B. | Continuous duty motors |
| C. | Short time rated motors |
| D. | None of the above |
| Answer» C. Short time rated motors | |
| 11. |
is preferred for synthetic fibre mills. |
| A. | Synchronous motor |
| B. | Reluctance motor |
| C. | Series motor |
| D. | Shunt motor |
| Answer» B. Reluctance motor | |
| 12. |
Ward-Leonard controlled D.C. drives are generally used for excavators. |
| A. | Light duty |
| B. | Medium duty |
| C. | Heavy duty |
| D. | All of the above |
| Answer» C. Heavy duty | |
| 13. |
Which of the following motors is used for elevators ? |
| A. | Induction motor |
| B. | Synchronous motor |
| C. | Capacitor start single phase motor |
| D. | Any of the above |
| Answer» A. Induction motor | |
| 14. |
Which part of a motor needs maximum attention for maintenance ? |
| A. | Frame |
| B. | Rearing |
| C. | Stator winding |
| D. | Rotor winding |
| Answer» B. Rearing | |
| 15. |
need frequent starting and stopping of electric motors, |
| A. | Paper mills |
| B. | Grinding mills |
| C. | Air-conditioners |
| D. | Lifts and hoists |
| Answer» D. Lifts and hoists | |
| 16. |
Which feature, while selecting a.motor for centrifugal pump, will be of least significance ? |
| A. | Starting characteristics |
| B. | Operating speed |
| C. | Horse power |
| D. | Speed control |
| Answer» D. Speed control | |
| 17. |
motor is a constant speed motor. |
| A. | Synchronous motor |
| B. | Schrage motor |
| C. | Induction motor |
| D. | Universal motor |
| Answer» A. Synchronous motor | |
| 18. |
The starting torque in case of centrifugal pumps is generally |
| A. | less than running torque |
| B. | same as running torque |
| C. | slightly more than running torque |
| D. | double the running torque |
| Answer» A. less than running torque | |
| 19. |
Which of the following motors are best for the rolling mills ? |
| A. | Single phase motors |
| B. | Squirrel cage induction motors |
| C. | Slip ring induction motors |
| D. | D.C. motors |
| Answer» D. D.C. motors | |
| 20. |
is not a part of ball bearing ? |
| A. | Inner race |
| B. | Outer race |
| C. | Cage |
| D. | Bush |
| Answer» D. Bush | |
| 21. |
The starting torque of a D.C. motor is independent of which of the following? |
| A. | Flux |
| B. | Armature current |
| C. | Flux and armature current |
| D. | Speed |
| Answer» D. Speed | |
| 22. |
Rotor of a motor is usually supported on bearings. |
| A. | ball or roller |
| B. | needle |
| C. | bush |
| D. | thrust |
| Answer» A. ball or roller | |
| 23. |
For which of the following applications D.C. motors are still preferred? |
| A. | High efficiency operation |
| B. | Reversibility |
| C. | Variable speed drive |
| D. | High starting torque |
| Answer» C. Variable speed drive | |
| 24. |
In a paper mill where constant speed is required |
| A. | synchronous motors are preferred |
| B. | A.C. motors are preferred |
| C. | individual drive is preferred |
| D. | group drive is preferred |
| Answer» C. individual drive is preferred | |
| 25. |
A reluctance motor |
| A. | is provided with slip rings |
| B. | requires starting gear |
| C. | has high cost |
| D. | is compact |
| Answer» D. is compact | |
| 26. |
The size of an excavator is usually expressed in terms of |
| A. | ‘crowd’ motion |
| B. | angle of swing |
| C. | cubic metres |
| D. | travel in metres |
| Answer» C. cubic metres | |
| 27. |
For blowers which of the following motor is preferred ? |
| A. | D.C. series motor |
| B. | D.C. shunt motor |
| C. | Squirrel cage induction motor |
| D. | Wound rotor induction motor |
| Answer» B. D.C. shunt motor | |
| 28. |
Belted slip ring induction motor is almost invariably used for |
| A. | water pumps |
| B. | jaw crushers |
| C. | centrifugal blowers |
| D. | none of the above |
| Answer» B. jaw crushers | |
| 29. |
Which of the following is essentially needed while selecting a motor ? |
| A. | Pulley |
| B. | Starter |
| C. | Foundation pedal |
| D. | Bearings |
| Answer» B. Starter | |
| 30. |
Reluctance motor is a |
| A. | variable torque motor |
| B. | low torque variable speed motor |
| C. | self starting type synchronous motor |
| D. | low noise, slow speed motor |
| Answer» C. self starting type synchronous motor | |
| 31. |
method of starting a three phase induction motor needs six terminals. |
| A. | Stardelta |
| B. | Resistance starting |
| C. | Auto-transformer |
| D. | None of the above |
| Answer» A. Stardelta | |
| 32. |
In method of staging three phase induction motors the starting voltage is not reduced. |
| A. | auto-transformer |
| B. | star-delta |
| C. | slip ring |
| D. | any of the above |
| Answer» C. slip ring | |
| 33. |
In jaw crushers a motor has to often start against load. |
| A. | heavy |
| B. | medium |
| C. | normal |
| D. | low |
| Answer» A. heavy | |
| 34. |
For a motor-generator set which of the following motors will be preferred ? |
| A. | Synchronous motor |
| B. | Slip ring induction motor |
| C. | Pole changing induction motor |
| D. | Squirrel cage induction motor |
| Answer» A. Synchronous motor | |
| 35. |
Which of the following motors is usually preferred for kiln drives? |
| A. | Cascade controlled A.C. motor |
| B. | Slip ring induction motor |
| C. | Three phase shunt wound com-mutator motor |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 36. |
Heat control switches are used in |
| A. | transformers |
| B. | cooling ranges |
| C. | three phase induction motors |
| D. | single phase |
| Answer» B. cooling ranges | |
| 37. |
has relatively wider range of speed control. |
| A. | Synchronous motor |
| B. | Ship ring induction motor |
| C. | Squirrel cage induction motor |
| D. | D.C. shunt motor |
| Answer» D. D.C. shunt motor | |
| 38. |
In squirrel cage induction motors which of the following methods of starting cannot be used ? |
| A. | Resistance in rotor circuit |
| B. | Resistance in stator circuit |
| C. | Auto-transformer starting |
| D. | Star-delta starting |
| Answer» A. Resistance in rotor circuit | |
| 39. |
In which of the following applications the load on motor changes in cyclic order? |
| A. | Electric shovels |
| B. | Cranes |
| C. | Rolling mills |
| D. | All of the above |
| Answer» D. All of the above | |
| 40. |
Flame proof motors are used in |
| A. | paper mills |
| B. | steel mills |
| C. | moist atmospheres |
| D. | explosive atmospheres |
| Answer» D. explosive atmospheres | |
| 41. |
Which of the following machines has heavy fluctuation of load ? |
| A. | Printing machine |
| B. | Punching machine |
| C. | Planer |
| D. | Lathe |
| Answer» B. Punching machine | |
| 42. |
For derries and winches which of the following drives can be used ? |
| A. | Pole changing squirrel cage motors |
| B. | D.C. motors with Ward-leonard con-trol |
| C. | A.C. slip ring motors with variable resistance |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 43. |
Battery operated scooter for braking uses |
| A. | plugging |
| B. | mechanical braking |
| C. | regenerative braking |
| D. | rheostatic braking |
| Answer» B. mechanical braking | |
| 44. |
has least range of speed control. |
| A. | Slip ring induction motor |
| B. | Synchronous motor |
| D. | C. shunt motor |
| Answer» B. Synchronous motor | |
| 45. |
has the least value of starting torque to full load torque ratio. |
| A. | D.C. shunt motor |
| B. | D.C. series motor |
| C. | Squirrel cage induction motor |
| D. | Slip ring induction motor |
| Answer» C. Squirrel cage induction motor | |
| 46. |
In case of speed control by injecting e.m.f. in the rotor circuit is possible, |
| A. | d.c. shunt motor |
| B. | schrage motor |
| C. | synchronous motor |
| D. | slip ring induction motor |
| Answer» D. slip ring induction motor | |
| 47. |
A pony motor is used for the starting which of the following motors ? |
| A. | Squirel cage induction motor |
| B. | Schrage motor |
| C. | Synchronous motor |
| D. | None of the above |
| Answer» C. Synchronous motor | |
| 48. |
In the speed can be varied by changing the position of brushes. |
| A. | slip ring motor |
| B. | schrage motor |
| C. | induction motor |
| D. | repulsion motor |
| Answer» B. schrage motor | |
| 49. |
In which of the following applications variable speed operation is preferred ? |
| A. | Exhaust fan |
| B. | Ceiling fan |
| C. | Refrigerator |
| D. | Water pump |
| Answer» B. Ceiling fan | |
| 50. |
Heavy duty cranes are used in |
| A. | ore handling plants |
| B. | steel plants |
| C. | heavy engineering workshops |
| D. | all of the above |
| Answer» D. all of the above | |
| 51. |
The travelling speed of cranes varies from |
| A. | 20 to 30 m/s |
| B. | 10 to 15 m/s |
| C. | 5 to 10 m/s |
| D. | 1 to 2.5 m/s |
| Answer» D. 1 to 2.5 m/s | |
| 52. |
Besides a constant speed a synchronous rotor possesses which of the following advantages ? |
| A. | Lower cost |
| B. | Better efficiency |
| C. | High power factor |
| D. | All of the above |
| Answer» C. High power factor | |
| 53. |
By the use of which of the followingm D.C. can be obtained from AC? |
| A. | Silicon diodes |
| B. | Mercury arc rectifier |
| C. | Motor generator set |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 54. |
Which of the following motors is preferred when quick speed reversal is the main consideration? |
| A. | Squirrel cage induction motor |
| B. | Wound rotor induction motor |
| C. | Synchronous motor |
| D. | D.C. motor |
| Answer» D. D.C. motor | |
| 55. |
Which ofthefollowing motors is preferred when smooth and precise speed control over a wide range is desired ? |
| A. | D.C. motor |
| B. | Squirrel cage induction motor |
| C. | Wound rotor induction motor |
| D. | Synchronous motor |
| Answer» A. D.C. motor | |
| 56. |
For crane travel which of the following motors is normally used ? |
| A. | Synchronous motor |
| B. | D.C. differentially compound motor |
| C. | Ward-Leonard controlled |
| D. | C. shunt motor |
| Answer» D. C. shunt motor | |
| 57. |
The capacity of a crane is expressed in terms of |
| A. | type of drive |
| B. | span |
| C. | tonnes |
| D. | any of the above |
| Answer» C. tonnes | |
| 58. |
The characteristics of drive for crane hoisting and lowering are which of the following ? |
| A. | Precise control |
| B. | Smooth movement |
| C. | Fast speed control |
| D. | All of the above |
| Answer» D. All of the above | |
| 59. |
Which of the following motors is preferred for boom hoist of a travelling crane? |
| A. | Single phase motor |
| B. | Synchronous motor |
| C. | A.C. slip ring motor |
| D. | Ward-Leonard controlled D.C. shunt motor |
| Answer» C. A.C. slip ring motor | |
| 60. |
A wound rotor induction motor is preferred, as compared to squirrel cage induction motor, when major consideration is |
| A. | slop speed operation |
| B. | high starting torque |
| C. | low windage losses |
| D. | all of the above |
| Answer» B. high starting torque | |
| 61. |
Which of the following motors has series characteristics ? |
| A. | Shaded pole motor |
| B. | Repulsion motor |
| C. | Capacitor start motor |
| D. | None of the above |
| Answer» B. Repulsion motor | |
| 62. |
Which of the following happens when star-delta starter is used ? |
| A. | Starting voltage is reduced |
| B. | Starting current is reduced |
| C. | Both (A) and (B) |
| D. | None of the above |
| Answer» C. Both (A) and (B) | |
| 63. |
For a D.C. shunt motor which of the following is incorrect 7 |
| A. | Unsuitable for heavy duty starting |
| B. | Torque varies as armature current |
| C. | Torque-armature current is a straight line |
| D. | Torque is zero for zero armature current |
| Answer» A. Unsuitable for heavy duty starting | |
| 64. |
For which of the following applications motor has to start with high acceleration? |
| A. | Oil expeller |
| B. | Floor mill |
| C. | Lifts and hoists |
| D. | Centrifugal pump |
| Answer» C. Lifts and hoists | |
| 65. |
Which of the following types of motor enclosure is safest ? |
| A. | Totally enclosed |
| B. | Totally enclosed fan cooled |
| C. | Open type |
| D. | Semi closed |
| Answer» B. Totally enclosed fan cooled | |
| 66. |
While selecting motor for an air conditioner which of the following characteristics is of great importance ? |
| A. | Type of bearings |
| B. | Type of enclosure |
| C. | Noise |
| D. | Arrangement for power transmis¬sion |
| Answer» C. Noise | |
| 67. |
The diameter of the rotor shaft for an electric motor depends on which of the following ? |
| A. | r.p.m. only |
| B. | Horse power only |
| C. | Horse power and r.p.m. |
| D. | Horse power, r.p.m. and power factor |
| Answer» C. Horse power and r.p.m. | |
| 68. |
Which of the following alternatives will be cheaper ? |
| A. | A 100 H.P. AC. three phase motor |
| B. | Four motors of 25 H.P. each |
| C. | Five motors of 20 H.P. each |
| D. | Ten motors of 10 H.P. each |
| Answer» A. A 100 H.P. AC. three phase motor | |
| 69. |
The cost of an induction motor will increase as |
| A. | horsepower rating increases but r.p.m. decreases |
| B. | horsepower rating decreases but r.p.m. increases |
| C. | horsepower rating and operating speed increases |
| D. | horsepower rating and operating speed decreases |
| Answer» A. horsepower rating increases but r.p.m. decreases | |
| 70. |
In series motor which of the following methods can be used for changing the flux per pole ? |
| A. | Tapped field control |
| B. | Diverter field control |
| C. | Series-parallel control |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 71. |
Word Leonard controlled DC Drives are generally used for..... excavators |
| A. | Light duty |
| B. | Medium duty |
| C. | Heavy duty |
| D. | All of the above |
| Answer» C. Heavy duty | |
| 72. |
......... is preferred for automatic drives |
| A. | Synchronous motors |
| B. | Word Leonard controlled DC motors |
| C. | None of the above |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 73. |
The load cycle for a motor driving a power press will be ......... |
| A. | Variable load |
| B. | Continuous |
| C. | Continuous but periodical |
| D. | Intermittent and variable load |
| Answer» D. Intermittent and variable load | |
| 74. |
A reluctance motor........ |
| A. | Is provided with slip rings |
| B. | Requires starting gear |
| C. | Has high cost |
| D. | Is compact |
| Answer» D. Is compact | |
| 75. |
The size of an excavator is usually expressed in terms of |
| A. | Crowd motion |
| B. | Angle of swing |
| C. | Cubic metres |
| D. | Travel in metres |
| Answer» C. Cubic metres | |
| 76. |
In jaw crushers a motor has to often start against....... load |
| A. | Heavy |
| B. | Medium |
| C. | Normal |
| D. | Low |
| Answer» A. Heavy | |
| 77. |
........has least range of speed control |
| A. | Slip ring induction motor |
| B. | Synchronous motor |
| C. | DC shunt motor |
| D. | Schrage motor |
| Answer» B. Synchronous motor | |
| 78. |
In series motor which of the following methods can be used for changing the flux per pole? |
| A. | Tapped field control |
| B. | Diverter field control |
| C. | Series-parallel control |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 79. |
Which of the following alternatives will be cheaper ? |
| A. | A 100 HP ac three phase motor |
| B. | Four motors of 25 HP each |
| C. | Five motors of 20 HP each |
| D. | 10 motors of 10 HP each |
| Answer» A. A 100 HP ac three phase motor | |
| 80. |
By the use of which of the following DC can be obtained from AC? |
| A. | Silicon diodes |
| B. | Mercury arc rectifier |
| C. | Motor generator set |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 81. |
Besides a constant speed a synchronous rotor possesses which of the following advantages ? |
| A. | Lower cost |
| B. | Better efficiency |
| C. | High power factor |
| D. | All of the above |
| Answer» C. High power factor | |
| 82. |
Which of the following types of motor and enclosure is safest |
| A. | Totally enclosed |
| B. | Totally enclosed fan cooled |
| C. | Open time |
| D. | Semi closed |
| Answer» B. Totally enclosed fan cooled | |
| 83. |
Which feature while selecting a motor for centrifugal pump will be of least significance? |
| A. | Starting characteristics |
| B. | Operating speed |
| C. | Horse power |
| D. | Speed control |
| Answer» D. Speed control | |
| 84. |
Which part of a motor needs maximum attention for maintenance? |
| A. | Frame |
| B. | Bearing |
| C. | Stator winding |
| D. | Rotor winding |
| Answer» B. Bearing | |
| 85. |
While selecting an electric motor for a floor Mill, which electrical characteristics will be of least significance ? |
| A. | Running characteristics |
| B. | Starting characteristics |
| C. | Efficiency |
| D. | Breaking |
| Answer» D. Breaking | |
| 86. |
Which off the following motors is used for elevators? |
| A. | Induction motor |
| B. | Synchronous motor |
| C. | Capacitor start single phase motor |
| D. | Any of the above |
| Answer» A. Induction motor | |
| 87. |
...........is preferred for synthetic fibre mails |
| A. | Synchronous motor |
| B. | Reluctance motor |
| C. | Series motor |
| D. | Shunt motor |
| Answer» B. Reluctance motor | |
| 88. |
For derries and winches which of the following drives can be used ? |
| A. | Pole changing squirrel cage motors |
| B. | DC motors with word Leonard control |
| C. | AC slip rings motors with a variable resistance |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 89. |
In........ method of starting three phase induction motors the starting voltage is not reduced |
| A. | Auto transformer |
| B. | Star Delta |
| C. | Slip ring |
| D. | Any of the above |
| Answer» C. Slip ring | |
| 90. |
For which off the following applications DC motors are still preferred? |
| A. | High operation |
| B. | Variable speed drive |
| C. | High starting torque |
| D. | Reversibility |
| Answer» B. Variable speed drive | |
| 91. |
Rotor of the motor is usually supported on........... bearings |
| A. | Ball or roller |
| B. | Needle |
| C. | Thrust |
| D. | Bush |
| Answer» A. Ball or roller | |
| 92. |
.............method of starting a three phase induction motor needs six terminals |
| A. | Resistance starting |
| B. | Auto transformer |
| C. | None of the above |
| D. | Star delta |
| Answer» A. Resistance starting | |
| 93. |
In a paper mill where constant speed is required |
| A. | Synchronous motors are preferred |
| B. | AC motors are preferred |
| C. | Individual drive is preferred |
| D. | Group drive is preferred |
| Answer» C. Individual drive is preferred | |
| 94. |
........is not a part of ball bearing |
| A. | Inner race |
| B. | Outer race |
| C. | Cage |
| D. | Bush |
| Answer» D. Bush | |
| 95. |
A pony motor is used for the starting which of the following motors ? |
| A. | Squirrel cage induction motor |
| B. | Schrage motor |
| C. | Synchronous motor |
| D. | None of the above |
| Answer» C. Synchronous motor | |
| 96. |
........ has relatively wider range of speed control |
| A. | Synchronous motor |
| B. | Slip ring induction motor |
| C. | Squirrel case induction motor |
| D. | DC shunt motor |
| Answer» D. DC shunt motor | |
| 97. |
Heat control switches are used in |
| A. | Transformers |
| B. | Cooling ranges |
| C. | Three phase induction motors |
| D. | Single face |
| Answer» B. Cooling ranges | |
| 98. |
An elevator Drive is required to operate in |
| A. | One quadrant only |
| B. | Two quadrants |
| C. | Three quadrants |
| D. | Four quadrants |
| Answer» D. Four quadrants | |
| 99. |
Belt conveyors offer ..........starting torque |
| A. | High |
| B. | Low |
| C. | Medium |
| D. | Zero |
| Answer» A. High | |
| 100. |
While selecting a motor for air-conditioner the feature of utmost importance is |
| A. | Type of enclosure |
| B. | Type of bearing |
| C. | Noise |
| D. | Power transmission arrangement |
| Answer» C. Noise | |
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