MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 27 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Machines knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In a 3-phase cylindrical rotor alternator the _________ |
| A. | field mmf leads air gap flux, air gap flux leads armature flux |
| B. | field mmf leads air gap flux, air gap flux lags armature flux |
| C. | armature mmf leads air gap flux and air gap flux leads field flux |
| D. | armature mmf leads air gap flux and air gap flux lags field flux |
| Answer» B. field mmf leads air gap flux, air gap flux lags armature flux | |
| 2. |
The power factor of an alternator under short circuit condition will be almost near ____________ |
| A. | zero lagging |
| B. | zero leading |
| C. | unity |
| D. | depends on the type of the alternator |
| Answer» B. zero leading | |
| 3. |
Out of the given statements about the cylindrical rotor alternator, mark the correct. |
| A. | A is false, B is true |
| B. | Only A is true |
| C. | Only B is true |
| D. | Both A and B are trueView Answer |
| Answer» B. Only A is true | |
| 4. |
Below are the statements about cylindrical rotor alternator. |
| A. | Only A is true |
| B. | Only B is true |
| C. | A is true, B is false |
| D. | A and B both are trueView Answer |
| Answer» E. | |
| 5. |
The zero power characteristics used in the Potier plot can be obtained by loading the alternator using ___________ |
| A. | synchronous motor |
| B. | lamp load |
| C. | dc motor |
| D. | induction motor |
| Answer» B. lamp load | |
| 6. |
Synchronous motor has been preferred for driving the loads requiring high power at low speeds. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 7. |
The practical speed ranges for the thermal, nuclear and hydel power plants is (in rpm)? |
| A. | 3000, 3000, 300 |
| B. | 3000, 300, 300 |
| C. | 1500, 1500, 3000 |
| D. | 1000, 500, 3000 |
| Answer» B. 3000, 300, 300 | |
| 8. |
Choose the appropriate synchronous generators used in the thermal power stations. |
| A. | (i), (ii), (iv) |
| B. | (ii), (iii), (v) |
| C. | (i), (iii) |
| D. | (ii), (iii), (iv), (v)View Answer |
| Answer» B. (ii), (iii), (v) | |
| 9. |
A synchronous machine with its field winding on stator and polyphase armature winding on rotor. At steady state, its air gap field is? |
| A. | stationary w.r.t. stator |
| B. | rotating at double the speed Ns w.r.t. rotor |
| C. | rotating in direction opposite to rotor |
| D. | all of the mentioned |
| Answer» E. | |
| 10. |
The condition which allows the torques to be taken care for choosing a synchronous motor is/are? |
| A. | starting torque |
| B. | pull-in torque |
| C. | pull-out torque |
| D. | all of the mentioned |
| Answer» E. | |
| 11. |
We prefer induction motor over synchronous motor due to ___________ |
| A. | no requirement of dc supply |
| B. | starting problems |
| C. | sensitive to environment |
| D. | all of the mentioned |
| Answer» B. starting problems | |
| 12. |
Synchronous compensators are mainly employed for ___________ |
| A. | compensating reactive power |
| B. | compensating real power |
| C. | improving power factor |
| D. | compensating field flux |
| Answer» B. compensating real power | |
| 13. |
One of the most prominent component of base loads is ___________ |
| A. | synchronous generator |
| B. | induction generator |
| C. | dc series generator |
| D. | all of the mentioned |
| Answer» B. induction generator | |
| 14. |
THE_PRACTICAL_SPEED_RANGES_FOR_THE_THERMAL,_NUCLEAR_AND_HYDEL_POWER_PLANTS_IS_(IN_RPM)?$ |
| A. | 3000,3000,300 |
| B. | 3000,300,300 |
| C. | 1500,1500,3000 |
| D. | 1000,500,3000 |
| Answer» B. 3000,300,300 | |
| 15. |
The zero power characteristics used in the Potier plot can be obtained by loading the alternator using$ |
| A. | synchronous motor |
| B. | lamp load |
| C. | dc motor |
| D. | induction motor |
| Answer» B. lamp load | |
| 16. |
Synchronous_motor_has_been_preferred_for_driving_the_loads_requiring_high_power_at_low_speeds.$ |
| A. | True |
| B. | False |
| Answer» B. False | |
| 17. |
In a 3-phase cylindrical rotor alternator |
| A. | field mmf leads air gap flux, air gap flux leads armature flux |
| B. | field mmf leads air gap flux, air gap flux lags armature flux |
| C. | armature mmf leads air gap flux and air gap flux leads field flux |
| D. | armature mmf leads air gap flux and air gap flux lags field flux |
| Answer» B. field mmf leads air gap flux, air gap flux lags armature flux | |
| 18. |
The power factor of an alternator under short circuit condition will be almost near |
| A. | zero lagging |
| B. | zero leading |
| C. | unity |
| D. | depends on the type of the alternator |
| Answer» B. zero leading | |
| 19. |
Out of the given statements about the cylindrical rotor alternator, mark the correct |
| A. | |
| B. | |
| C. | A is false, B is true |
| Answer» B. | |
| 20. |
Choose the appropriat? |
| A. | |
| B. | cylindrical rotor |
| C. | slip rings and brushes |
| Answer» B. cylindrical rotor | |
| 21. |
A synchronous machine with its field winding on rotor and polyphase armature winding on stator. At steady state running condition, its air gap field is |
| A. | stationary w.r.t. stator |
| B. | rotating at double the Ns w.r.t. rotor |
| C. | rotating at -Ns w.r.t. rotor |
| D. | stationary w.r.t. rotor. |
| Answer» E. | |
| 22. |
A synchronous machine with its field winding on stator and polyphase armature winding on rotor. At steady state, its air gap field is |
| A. | stationary w.r.t. stator |
| B. | rotating at double the speed Ns w.r.t. rotor |
| C. | rotating in direction opposite to rotor |
| D. | all of the mentioned |
| Answer» E. | |
| 23. |
The condition which allows the torques to be taken care for choosing a synchronous motor is/are |
| A. | starting torque |
| B. | pull-in torque |
| C. | pull-out torque |
| D. | all of the mentioned |
| Answer» E. | |
| 24. |
We prefer induction motor over synchronous motor due to |
| A. | no requirement of dc supply |
| B. | starting problems |
| C. | sensitive to environment |
| D. | all of the mentioned |
| Answer» B. starting problems | |
| 25. |
Synchronous compensators are mainly employed for |
| A. | compensating reactive power |
| B. | compensating real power |
| C. | improving power factor |
| D. | compensating field flux |
| Answer» B. compensating real power | |
| 26. |
______ alternator is used in thermal stations and ______ alternator is used in hydel plants. |
| A. | Cylindrical-rotor, salient pole |
| B. | Salinet pole, cylindrical-rotor |
| C. | Salient pole, Reluctance |
| D. | Cylindrical-rotor, cylindrical-rotor |
| Answer» B. Salinet pole, cylindrical-rotor | |
| 27. |
One of the most prominent component of base loads is |
| A. | synchronous generator |
| B. | induction generator |
| C. | dc series generator |
| D. | all of the mentioned |
| Answer» B. induction generator | |