MCQOPTIONS
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MCQOPTIONS
This section includes 14 Mcqs, each offering curated multiple-choice questions to sharpen your Electric Drives knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Calculate the three-phase power using the following data: Vp=23 V, Ip=23 A, ∅=60. |
| A. | 793.5 W |
| B. | 790 W |
| C. | 792 W |
| D. | 791 W |
| Answer» B. 790 W | |
| 2. |
A 3 – phase, 4 pole IM is supplied from a 40 Hz source. Calculate rotor frequency when the rotor runs 100 rpm. |
| A. | 35 Hz |
| B. | 36.6 Hz |
| C. | 9 Hz |
| D. | 8 Hz |
| Answer» C. 9 Hz | |
| 3. |
What is the speed of the 11th order harmonics in the induction motor? |
| A. | Ns |
| B. | Ns/11 |
| C. | 2×Ns |
| D. | Nr |
| Answer» C. 2×Ns | |
| 4. |
What is the speed of the 6th order time harmonics in the induction motor? |
| A. | Ns |
| B. | Ns/6 |
| C. | 6×Ns |
| D. | 0 |
| Answer» D. 0 | |
| 5. |
Single phase induction motor is self-starting. |
| A. | True |
| B. | False |
| Answer» C. | |
| 6. |
Magnetizing current in the induction motor is ______ |
| A. | more than the transformer |
| B. | equal as a transformer |
| C. | less than the transformer |
| D. | 0 |
| Answer» B. equal as a transformer | |
| 7. |
The ratio of the rotor copper loss and air gap power is _______ |
| A. | s |
| B. | 1-s |
| C. | 1+s |
| D. | 0 |
| Answer» B. 1-s | |
| 8. |
What will happen if we increase the air gap in the induction motor? |
| A. | Power factor will reduce |
| B. | Power factor will increase |
| C. | Reduction in harmonics |
| D. | Speed will increase |
| Answer» B. Power factor will increase | |
| 9. |
The relative speed between the rotor and stator in the induction motor is ______ |
| A. | Nr |
| B. | Ns-Nr |
| C. | Ns+Nr |
| D. | 0 |
| Answer» B. Ns-Nr | |
| 10. |
The relative speed between the stator magnetic field and stator in the induction motor is ______ |
| A. | Ns |
| B. | Ns-Nr |
| C. | Ns+Nr |
| D. | 0 |
| Answer» B. Ns-Nr | |
| 11. |
The relative speed between the stator magnetic field and rotor in the synchronous generator is ______ |
| A. | Ns |
| B. | Ns-Nr |
| C. | Ns+Nr |
| D. | 0 |
| Answer» E. | |
| 12. |
The relative speed between the stator magnetic field and rotor in the induction motor is ______ |
| A. | Ns |
| B. | Ns-Nr |
| C. | Ns+Nr |
| D. | 0 |
| Answer» C. Ns+Nr | |
| 13. |
For motoring mode, the phase angle between the stator phase voltage and stator phase current should be _______ |
| A. | < 90° |
| B. | > 90° |
| C. | < 40° |
| D. | 180° |
| Answer» B. > 90° | |
| 14. |
Power input to an induction motor is given by _________ |
| A. | 3VpIpcosΦ |
| B. | 2VpIpcosΦ |
| C. | VpIpcosΦ |
| D. | 5VpIpcosΦ |
| Answer» B. 2VpIpcosΦ | |