300+ TOP Industrial Drivers MCQ Questions and Answers

Industrial Drivers Multiple Choice Questions :-

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. Cost
E. All of the above

Answer: E

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. Speed control range and its nature
E. All of the above

Answer: E

3. Which of the following motors is preferred for traction work ?
A.      Universal motor
B.      D.C. series motor
C. Synchronous motor
D. Three-phase induction motor

Answer: C

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

5. is preferred for automatic drives.
A.      Squirrel cage induction motor
B.      Synchronous motors
C. Ward-Leonard controlled D.C. motors
D. Any of the above

Answer: C

INDUSTRIAL DRIVES Objective Questions and Answers
INDUSTRIAL DRIVES Objective Questions

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

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

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

9. 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. Braking

Answer: D

10. Which of the following motors are pre-ferred for overhead travelling cranes ?
A. Slow speed motors
B. Continuous duty motors
C. Short time rated motors
D. None of the above

Answer: C

11. is preferred for synthetic fibre mills.
A.      Synchronous motor
B.      Reluctance motor
C. Series motor
D. Shunt motor

Answer: B

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

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

14. Which part of a motor needs maximum attention for maintenance ?
A.      Frame
B.      Rearing
C. Stator winding
D. Rotor winding

Answer: B

15. need frequent starting and stopping of electric motors,
A.      Paper mills
B.      Grinding mills
C. Air-conditioners
D. Lifts and hoists

Answer: D

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

17. _______ motor is a constant speed motor.
A. Synchronous motor
B. Schrage motor
C. Induction motor
D. Universal motor

Answer: A

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

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

20. is not a part of ball bearing ?
A. Inner race
B. Outer race
C. Cage
D. Bush

Answer: D

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

22. Rotor of a motor is usually supported on _______ bearings.
A.      ball or roller
B.      needle
C.      bush
D.      thrust

Answer: A

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

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

25. A reluctance motor
A. is provided with slip rings
B. requires starting gear
C. has high cost
D. is compact

Answer: D

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

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

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

29. Which of the following is essentially needed while selecting a motor ?
A.      Pulley
B.      Starter
C. Foundation pedal
D. Bearings

Answer: B

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

31. method of starting a three phase induction motor needs six terminals.
A. Star-delta
B. Resistance starting
C. Auto-transformer
D. None of the above

Answer: A

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

33. In jaw crushers a motor has to often start against ______ load.
A. heavy
B. medium
C. normal
D. low

Answer: A

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

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

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36. Heat control switches are used in
A. transformers
B. cooling ranges
C. three phase induction motors
D. single phase

Answer: B

37. has relatively wider range of speed control.
A.      Synchronous motor
(6)     Ship ring induction motor
C. Squirrel cage induction motor
D. D.C. shunt motor

Answer: D

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

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

40. Flame proof motors are used in
A.      paper mills
B.      steel mills
C. moist atmospheres
D. explosive atmospheres

Answer: D

41. Which of the following machines has heavy fluctuation of load ?
A. Printing machine
B. Punching machine
C. Planer
D. Lathe

Answer: B

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

43. Battery operated scooter for braking uses
A.      plugging
B.      mechanical braking
C. regenerative braking
D. rheostatic braking

Answer: B

44. has least range of speed control.
A. Slip ring induction motor
B. Synchronous motor
C. D.C. shunt motor
D. Schrage motor

Answer: B

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

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

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

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

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

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

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

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

53. By the use of which of the following m 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

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
E. Synchronous motor
D.      D.C. motor

Answer: D

55. Which of the following 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

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
D. AC. slip ring motor

Answer: D

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

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

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

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

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

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

63. For a D.C. shunt motor which of the following is incorrect ?
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

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

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

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
E. None of the above

Answer: C

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

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

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

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

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2 thoughts on “300+ TOP Industrial Drivers MCQ Questions and Answers

  1. Great…I found these questions now, Bad luck. Many similar questions are came in my PSTCL je and SSA exam ..

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