MCQOPTIONS
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MCQOPTIONS
This section includes 11 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. |
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 | |
| 4. |
Synchronous motor has been preferred for driving the loads requiring high power at low speeds. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 5. |
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 | |
| 6. |
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. | |
| 7. |
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. | |
| 8. |
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. | |
| 9. |
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 | |
| 10. |
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 | |
| 11. |
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 | |