MCQOPTIONS
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MCQOPTIONS
This section includes 28 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. |
Two three phase squirrel-cage induction generator are identical in all respects except the fact that the slot depths in machine B is more than that of A. Machine B as compared to machine A, will have _________ |
| A. | less pull out torque but better power factor |
| B. | more pull out torque but poor power factor |
| C. | less pull out torque and poor power factor |
| D. | more pull out torque and better power factor |
| Answer» B. more pull out torque but poor power factor | |
| 2. |
A 3-phase induction motor has full load efficiency of 0.7 and a maximum efficiency of 0.85. It is operated at a slip of 0.6 by reduced voltage method. The efficiency of the motor at this operating point is? |
| A. | less than 0.35 |
| B. | greater than 0.35 |
| C. | in the range of 0.8 to 0.2 |
| D. | none of the mentioned |
| Answer» B. greater than 0.35 | |
| 3. |
Which is the most acceptable application field where an induction generator can be used? |
| A. | wind power system |
| B. | steam power system |
| C. | hydro power system |
| D. | nuclear power station |
| Answer» B. steam power system | |
| 4. |
Choose the correct match for the corresponding characteristics of a 3-phase induction motor. |
| A. | A-II, B-III, C-I |
| B. | A-III, B-II, C-I |
| C. | A-III, B-I, C-II |
| D. | A-I, B-II, C-IIIView Answer |
| Answer» B. A-III, B-II, C-I | |
| 5. |
Induction generator can only work at leading reactive power. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 6. |
Induction generator is self excited machine. |
| A. | True |
| B. | False |
| Answer» C. | |
| 7. |
What is/are the shortcomings of an induction generator in real time system? |
| A. | It needs considerable amount of reactive power |
| B. | Efficiency is poor |
| C. | It can work at leading power factor only |
| D. | All of the mentioned |
| Answer» E. | |
| 8. |
I. Voltage of an externally excited induction generator can not be controlled. II. Frequency of an externally excited induction generator can be controlled. |
| A. | I is true, II is false |
| B. | I is true, II is true |
| C. | I is false, II is false |
| D. | I is false, II is true |
| Answer» B. I is true, II is true | |
| 9. |
Voltage build up in an isolated induction generator depends on ____________ |
| A. | A, B |
| B. | A, B, C |
| C. | B |
| D. | A, CView Answer |
| Answer» B. A, B, C | |
| 10. |
If the residual flux is absent in the rotor iron of the isolated induction generator ____________ |
| A. | it will not run |
| B. | it will run as induction motor |
| C. | it will burn the winding |
| D. | it will not affect the characteristic of the generator |
| Answer» B. it will run as induction motor | |
| 11. |
The magnetization curve in the induction generator working in isolation has similar characteristic as ____________ |
| A. | dc shunt generator |
| B. | dc cumulative field generator |
| C. | synchronous generator |
| D. | all of the mentioned |
| Answer» B. dc cumulative field generator | |
| 12. |
For an induction motor to work in isolation, it should have ____________ |
| A. | lagging reactive power source |
| B. | leading reactive power source |
| C. | leading reactive power sink |
| D. | any of the mentioned |
| Answer» B. leading reactive power source | |
| 13. |
A self excited induction generator ____________ |
| A. | must have static capacitor bank |
| B. | can have static capacitor bank |
| C. | should have static capacitor bank |
| D. | any of the mentioned |
| Answer» B. can have static capacitor bank | |
| 14. |
Induction generator ____________ |
| A. | can not work in isolation |
| B. | can work in isolation |
| C. | should work in parallel with synchronous generators |
| D. | any of the mentioned |
| Answer» D. any of the mentioned | |
| 15. |
A 3-phase induction motor can also be run as ______________ |
| A. | synchronous generator |
| B. | induction generator |
| C. | dc shunt motor |
| D. | any of the mentioned |
| Answer» C. dc shunt motor | |
| 16. |
INDUCTION_GENERATOR_IS_SELF_EXCITED_MACHINE.?$ |
| A. | True |
| B. | False |
| Answer» C. | |
| 17. |
WHAT_IS/ARE_THE_SHORTCOMINGS_OF_AN_INDUCTION_GENERATOR_IN_REAL_TIME_SYSTEM??$ |
| A. | It needs considerable amount of reactive power |
| B. | Efficiency is poor |
| C. | It can work at leading power factor only |
| D. | All of the mentioned |
| Answer» E. | |
| 18. |
Induction generator can only work at leading reactive power.$ |
| A. | True |
| B. | False |
| Answer» B. False | |
| 19. |
Two three phase squirrel-cage induction generator are identical in all respects except the fact that the slot depths in machine B is more than that of A. |
| A. | |
| B. | less pull out torque but better power factor |
| C. | more pull out torque but poor power factor |
| Answer» B. less pull out torque but better power factor | |
| 20. |
A 3-phase induction motor has full load efficiency of 0.7 and a maximum efficiency of 0.85. It is operated at a slip of 0.6 by reduced voltage method. The efficiency of the motor at this operating point is |
| A. | less than 0.35 |
| B. | greater than 0.35 |
| C. | in the range of 0.8 to 0.2 |
| D. | none of the mentioned |
| Answer» B. greater than 0.35 | |
| 21. |
The most acceptable application field where an induction generator cana be used is |
| A. | wind power system |
| B. | steam power system |
| C. | hydro power system |
| D. | nuclear power station |
| Answer» B. steam power system | |
| 22. |
I. Voltage of an externally excited induction generator can not be controlled? |
| A. | |
| B. | I is true, II is false |
| C. | I is true, II is true |
| Answer» B. I is true, II is false | |
| 23. |
If the residual flux is absent in the rotor iron of the isolated induction generator, |
| A. | it will not run. |
| B. | it will run as induction motor |
| C. | it will burn the winding |
| D. | it will not affect the characteristic of the generator |
| Answer» B. it will run as induction motor | |
| 24. |
The magnetization curve in the induction generator working in isolation has similar characteristic as |
| A. | dc shunt generator |
| B. | dc cumulative field generator |
| C. | synchronous generator |
| D. | all of the mentioned |
| Answer» B. dc cumulative field generator | |
| 25. |
For an induction motor to work in isolation, it should have |
| A. | lagging reactive power source |
| B. | leading reactive power source |
| C. | leading reactive power sink |
| D. | any of the mentioned |
| Answer» B. leading reactive power source | |
| 26. |
A self excited induction generator |
| A. | must have static capacitor bank |
| B. | can have static capacitor bank |
| C. | should have static capacitor bank |
| D. | any of the mentioned |
| Answer» B. can have static capacitor bank | |
| 27. |
Induction generator |
| A. | can not work in isolation |
| B. | can work in isolation |
| C. | should work in parallel with synchronous generators |
| D. | any of the mentioned |
| Answer» D. any of the mentioned | |
| 28. |
A 3-phase induction motor can also be run as |
| A. | synchronous generator |
| B. | induction generator |
| C. | dc shunt motor |
| D. | any of the mentioned |
| Answer» C. dc shunt motor | |