MCQOPTIONS
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MCQOPTIONS
This section includes 50 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering Questions knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
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» E. | |
| 2. |
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» D. Arrangement for power transmis¬sion | |
| 3. |
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» E. | |
| 4. |
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 | |
| 5. |
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» D. Three-phase induction motor | |
| 6. |
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. | |
| 7. |
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» D. Ward-Leonard controlled D.C. shunt motor | |
| 8. |
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» E. | |
| 9. |
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» E. | |
| 10. |
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 | |
| 11. |
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» E. | |
| 12. |
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 | |
| 13. |
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» D. travel in metres | |
| 14. |
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» F. | |
| 15. |
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» E. | |
| 16. |
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» D. Horse power, r.p.m. and power factor | |
| 17. |
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 | |
| 18. |
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. | |
| 19. |
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 | |
| 20. |
Rotor of a motor is usually supported on ___________________ bearings? |
| A. | ball or roller |
| B. | needle |
| C. | bush |
| D. | thrust |
| Answer» B. needle | |
| 21. |
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 | |
| 22. |
need frequent starting and stopping of electric motors ? |
| A. | Paper mills |
| B. | Grinding mills |
| C. | Air-conditioners |
| D. | Lifts and hoists |
| Answer» E. | |
| 23. |
________________ motor is a constant speed motor? |
| A. | Synchronous motor |
| B. | Schrage motor |
| C. | Induction motor |
| D. | Universal motor |
| Answer» B. Schrage motor | |
| 24. |
_________________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» B. Resistance starting | |
| 25. |
___________________is preferred for synthetic fibre mills? |
| A. | Synchronous motor |
| B. | Reluctance motor |
| C. | Series motor |
| D. | Shunt motor |
| Answer» C. Series motor | |
| 26. |
________________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 | |
| 27. |
___________________is not a part of ball bearing ? |
| A. | Inner race |
| B. | Outer race |
| C. | Cage |
| D. | Bush |
| Answer» E. | |
| 28. |
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. | |
| 29. |
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 | |
| 30. |
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» D. any of the above | |
| 31. |
In jaw crushers a motor has to often start against ____________________ load? |
| A. | heavy |
| B. | medium |
| C. | normal |
| D. | low |
| Answer» B. medium | |
| 32. |
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. | |
| 33. |
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 | |
| 34. |
Heavy duty cranes are used in________________? |
| A. | ore handling plants |
| B. | steel plants |
| C. | heavy engineering workshops |
| D. | all of the above |
| Answer» E. | |
| 35. |
Heat control switches are used in__________________? |
| A. | transformers |
| B. | cooling ranges |
| C. | three phase induction motors |
| D. | single phase |
| Answer» C. three phase induction motors | |
| 36. |
__________________ 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» E. | |
| 37. |
_______________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 | |
| 38. |
___________________has least range of speed control? |
| A. | Slip ring induction motor |
| B. | Synchronous motor |
| C. | D.C. shunt motor |
| D. | Schrage motor |
| Answer» C. D.C. shunt motor | |
| 39. |
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 | |
| 40. |
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» D. High starting torque | |
| 41. |
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» F. | |
| 42. |
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» B. Torque varies as armature current | |
| 43. |
Flame proof motors are used in_________________? |
| A. | paper mills |
| B. | steel mills |
| C. | moist atmospheres |
| D. | explosive atmospheres |
| Answer» E. | |
| 44. |
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» E. | |
| 45. |
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 | |
| 46. |
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 | |
| 47. |
Battery operated scooter for braking uses________________? |
| A. | plugging |
| B. | mechanical braking |
| C. | regenerative braking |
| D. | rheostatic braking |
| Answer» C. regenerative braking | |
| 48. |
Battery operated scooter for braking uses__________________? |
| A. | plugging |
| B. | mechanical braking |
| C. | regenerative braking |
| D. | rheostatic braking |
| Answer» C. regenerative braking | |
| 49. |
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 | |
| 50. |
A reluctance motor_________________? |
| A. | is provided with slip rings |
| B. | requires starting gear |
| C. | has high cost |
| D. | is compact |
| Answer» E. | |