MCQOPTIONS
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MCQOPTIONS
This section includes 15 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 value of the frequency if the inductive reactance is 60 and the value of the inductor is 4 H. |
| A. | 2.38 Hz |
| B. | 5.54 Hz |
| C. | 4.65 Hz |
| D. | 9.42 Hz |
| Answer» B. 5.54 Hz | |
| 2. |
Calculate mark to space ratio if the system is on for 4 sec and off time is 9 sec. |
| A. | .54 |
| B. | .44 |
| C. | .45 |
| D. | .46 |
| Answer» C. .45 | |
| 3. |
Calculate the value of the duty cycle if the system is on for 1 sec and off for 17 sec. |
| A. | .055 |
| B. | .781 |
| C. | .484 |
| D. | .947 |
| Answer» B. .781 | |
| 4. |
Calculate the reactive power in a 24.5 resistor. |
| A. | 0 VAR |
| B. | 5 VAR |
| C. | 8 VAR |
| D. | 9 VAR |
| Answer» B. 5 VAR | |
| 5. |
Reluctance motor operates at power factor of __________ |
| A. | .8 |
| B. | .2 |
| C. | .3 |
| D. | .9 |
| Answer» B. .2 | |
| 6. |
Calculate the value of Crest factor if Vpeak=798 V and Vr.m.s=489 V. |
| A. | 1.63 |
| B. | 1.54 |
| C. | 1.59 |
| D. | 1.26 |
| Answer» B. 1.54 | |
| 7. |
Calculate peak-peak voltage if Vmax=180 V and Vmin=60 V. |
| A. | 120 V |
| B. | 150 V |
| C. | 170 V |
| D. | 110 V |
| Answer» B. 150 V | |
| 8. |
Calculate the circuit turn-off time for 3- Fully controlled rectifier if the firing angle is 120 and supply frequency is 60 Hz. |
| A. | 1.8 msec |
| B. | 3.2 msec |
| C. | 6.3 msec |
| D. | 2.7 msec |
| Answer» E. | |
| 9. |
Calculate the circuit turn-off time for 3- Fully controlled rectifier if the firing angle is 27 and supply frequency is 50 Hz. |
| A. | 11.8 msec |
| B. | 14.4 msec |
| C. | 16.1 msec |
| D. | 16.5 msec |
| Answer» B. 14.4 msec | |
| 10. |
Increasing the stator poles ___________ the speed of Reluctance motor. |
| A. | Decreases |
| B. | Increases |
| C. | Remains the same |
| D. | Negative |
| Answer» B. Increases | |
| 11. |
Which of the following motor is used in recording instruments? |
| A. | Reluctance motor |
| B. | Induction motor |
| C. | Synchronous motor |
| D. | DC motor |
| Answer» B. Induction motor | |
| 12. |
Calculate the value of the Input power factor for 3- Fully controlled rectifier if the firing angle value is 90 . |
| A. | 0 |
| B. | .2 |
| C. | .3 |
| D. | .4 |
| Answer» B. .2 | |
| 13. |
An infinite bus-bar has _____________ |
| A. | Constant voltage |
| B. | Constant frequency |
| C. | Constant voltage and frequency |
| D. | constant speed |
| Answer» D. constant speed | |
| 14. |
Reluctance motor can operate on DC supply. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 15. |
Reluctance motors are singly-excited. |
| A. | True |
| B. | False |
| Answer» B. False | |