MCQOPTIONS
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MCQOPTIONS
This section includes 135 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
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» B. Same as running torque | |
| 2. |
________ 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» D. Slip ring induction motor | |
| 3. |
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» C. Low windage losses | |
| 4. |
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» D. None of the above | |
| 5. |
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» D. Centrifugal pump | |
| 6. |
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» E. | |
| 7. |
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» E. | |
| 8. |
Which of the following machines has heavy fluctuation of load? |
| A. | Printing machine |
| B. | Punching machine |
| C. | Planer |
| D. | Lathe |
| Answer» C. Planer | |
| 9. |
Flame proof motors are used in |
| A. | Paper mills |
| B. | Steel mills |
| C. | Moist atmospheres |
| D. | Explosive atmospheres |
| Answer» E. | |
| 10. |
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» C. Open type | |
| 11. |
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» D. Low noise, slow speed motor | |
| 12. |
Short time rated motors are preferred for overhead traveling cranes |
| A. | True |
| B. | False |
| Answer» B. False | |
| 13. |
Which of the following is essentially needed while selecting a motor? |
| A. | Pulley |
| B. | Starter |
| C. | Foundation pedal |
| D. | Bearings |
| Answer» C. Foundation pedal | |
| 14. |
By the use of which of the following D.C. can be obtained from AC.? |
| A. | Silicon diodes |
| B. | Mercury arc rectifier |
| C. | Motor generator set |
| D. | Any of the above |
| Answer» E. | |
| 15. |
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» E. | |
| 16. |
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» B. Squirrel cage induction motor | |
| 17. |
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» E. | |
| 18. |
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» E. | |
| 19. |
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» E. | |
| 20. |
Is not a part of ball bearing? |
| A. | Inner race |
| B. | Outer race |
| C. | Cage |
| D. | Bush |
| Answer» E. | |
| 21. |
________ need frequent starting and stopping of electric motors, |
| A. | Paper mills |
| B. | Grinding mills |
| C. | Air-conditioners |
| D. | Lifts and hoists |
| Answer» E. | |
| 22. |
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» C. Squirrel cage induction motor | |
| 23. |
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» E. | |
| 24. |
Which of the following motors are preferred for overhead traveling cranes? |
| A. | Slow speed motors |
| B. | Continuous duty motors |
| C. | Short time rated motors |
| D. | None of the above |
| Answer» D. None of the above | |
| 25. |
A reluctance motor |
| A. | Is provided with slip rings |
| B. | Requires starting gear |
| C. | Has high cost |
| D. | Is compact |
| Answer» E. | |
| 26. |
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» D. All of the above | |
| 27. |
Heavy duty cranes are used in |
| A. | Ore handling plants |
| B. | Steel plants |
| C. | Heavy engineering workshops |
| D. | All of the above |
| Answer» E. | |
| 28. |
The capacity of a crane is expressed in terms of |
| A. | Type of drive |
| B. | Span |
| C. | Tonnes |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 29. |
The size of an excavator is usually expressed in terms of |
| A. | "Crowd" motion |
| B. | Angle of swing |
| C. | Cubic meters |
| D. | Travel in meters |
| Answer» D. Travel in meters | |
| 30. |
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» E. | |
| 31. |
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» E. | |
| 32. |
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» B. Horsepower rating decreases but r.p.m. increases | |
| 33. |
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. | Autotransformer starting |
| D. | Star-delta starting |
| Answer» B. Resistance in stator circuit | |
| 34. |
Battery operated scooter for braking uses |
| A. | Plugging |
| B. | Mechanical braking |
| C. | Regenerative braking |
| D. | Rheostatic braking |
| Answer» C. Regenerative braking | |
| 35. |
In _________ method of staging three phase induction motors the starting voltage is not reduced. |
| A. | Autotransformer |
| B. | Star-delta |
| C. | Slip ring |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 36. |
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» C. Induction motor | |
| 37. |
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» D. Any of the above | |
| 38. |
__________ motor is a constant speed motor. |
| A. | Synchronous motor |
| B. | Schrage motor |
| C. | Induction motor |
| D. | Universal motor |
| Answer» B. Schrage motor | |
| 39. |
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» D. All of the above | |
| 40. |
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» B. Slip ring induction motor | |
| 41. |
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» E. | |
| 42. |
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 commutator motor |
| D. | Any of the above |
| Answer» E. | |
| 43. |
In which of the following applications variable speed operation is preferred? |
| A. | Exhaust fan |
| B. | Ceiling fan |
| C. | Refrigerator |
| D. | Water pump |
| Answer» C. Refrigerator | |
| 44. |
Is preferred for synthetic fibre mills. |
| A. | Synchronous motor |
| B. | Reluctance motor |
| C. | Series motor |
| D. | Shunt motor |
| Answer» C. Series motor | |
| 45. |
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» D. Group drive is preferred | |
| 46. |
__________ method of starting a three phase induction motor needs six terminals. |
| A. | Star-delta |
| B. | Resistance starting |
| C. | Autotransformer |
| D. | None of the above |
| Answer» B. Resistance starting | |
| 47. |
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» D. None of the above | |
| 48. |
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» C. Centrifugal blowers | |
| 49. |
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. Synchronous motor | |
| 50. |
For derris and winches which of the following drives can be used? |
| A. | Pole changing squirrel cage motors |
| B. | D.C. motors with Ward-Leonard control |
| C. | A.C. slip ring motors with variable resistance |
| D. | Any of the above |
| Answer» E. | |