MCQOPTIONS
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MCQOPTIONS
This section includes 10 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. |
The hydroelectric plants in the industry are best suited to ____________ |
| A. | closed circuit air cooling |
| B. | hydrogen gas |
| C. | direct water |
| D. | any of the mentioned |
| Answer» B. hydrogen gas | |
| 2. |
The iron losses in a saturated three phase alternator is lesser than the non-saturated three phase alternator. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 3. |
A peaky voltage supply is given to the 3 phase power transformer of the connection power system. These results into ____________ |
| A. | reduction in iron losses |
| B. | reduction in copper losses |
| C. | increase in iron losses |
| D. | reduction in noise |
| Answer» B. reduction in copper losses | |
| 4. |
A three phase induction motor is connected to the infinite bus operating at the normal conditions. There occurs an unbalancing in the supply, leading to ____________ |
| A. | unequal heating losses |
| B. | stopping of motor |
| C. | increase in lower |
| D. | none of the mentioned |
| Answer» B. stopping of motor | |
| 5. |
If one of the phases of RYB supply gets broken, then the temperature rise of the induction motor ____________ |
| A. | remains same as before |
| B. | reduces as compared to the normal operating temperature |
| C. | reduces to temperature rise of corresponding single phase induction motor |
| D. | increases |
| Answer» B. reduces as compared to the normal operating temperature | |
| 6. |
If one of the phases of the supply breaks down, then the connected three phase induction motor ____________ |
| A. | continues to run as a single phase induction motor, provided load does does not increase beyond 57.7% |
| B. | stops operating after few seconds |
| C. | continues to run as single phase induction motor |
| D. | continues to run as two phase induction motor |
| Answer» B. stops operating after few seconds | |
| 7. |
For squirrel cage and slip ring induction motor, cooling methods is efficient in ____________ |
| A. | squirrel cage induction motor |
| B. | slip ring induction motor |
| C. | both of the motors |
| D. | none of the mentioned |
| Answer» B. slip ring induction motor | |
| 8. |
In dc machine iron losses cause ____________ |
| A. | heating in core |
| B. | loss in efficiency |
| C. | rise in temperature of ventilating air |
| D. | all of the mentioned |
| Answer» B. loss in efficiency | |
| 9. |
If two series motors are identically coupled. One is running as motor while other as generator. For this combination, the iron losses and frictional losses are found identical for ____________ |
| A. | identical speed and excitation |
| B. | identical speed |
| C. | identical rating and construction |
| D. | none of the mentioned |
| Answer» B. identical speed | |
| 10. |
For the given traction application using a dc series motor for a starting time t is applied. If this method is replaced by a series-parallel control, giving 50% time for each series and parallel. The saving in the starting energy of ____________ |
| A. | 25% |
| B. | zero |
| C. | 50% |
| D. | 75% |
| Answer» B. zero | |