MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Power Electronics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
In a PWM inverter, if the frequency of the lowest harmonic is 180 Hz, then the frequency of the fundamental component would be ___________ |
| A. | 50 Hz |
| B. | 60 Hz |
| C. | 540 Hz |
| D. | 90 Hz |
| Answer» C. 540 Hz | |
| 2. |
Calculate the pulse width in case of MPM, if the amplitudes of square wave and triangular wave are respectively 2 V and 3 V respectively. 16 pulses per cycle are generated. |
| A. | 18° |
| B. | 7.5° |
| C. | 6.4° |
| D. | 9° |
| Answer» C. 6.4° | |
| 3. |
In an inverter, if the fundamental output frequency is 50 Hz, then the frequency of the lowest order harmonic will be |
| A. | 50 Hz |
| B. | 150 Hz |
| C. | 250 Hz |
| D. | 350 Hz |
| Answer» C. 250 Hz | |
| 4. |
In MPM the amplitudes of square wave and triangular wave are respectively 1 V and 2 V. For generating 5 pulses per half cycle, the pulse width should be ___________ |
| A. | 36° |
| B. | 24° |
| C. | 12° |
| D. | 18° |
| Answer» E. | |
| 5. |
In single-phase modulation of PWM inverters, the pulse width is 120°. For an input voltage of 220 V dc, the rms value of output voltage is |
| A. | 185 V |
| B. | 254 V |
| C. | 127 V |
| D. | 179 V |
| Answer» E. | |
| 6. |
Increasing the number of pulses (N), ____________ |
| A. | reduces the output voltage amplitude |
| B. | reduces the inverter efficiency |
| C. | improves the inverter efficiency |
| D. | none of the mentioned |
| Answer» C. improves the inverter efficiency | |
| 7. |
In case of sinusoidal pulse width modulation with MI < 1, if the number of pulses per half cycle (N) = 6, then |
| A. | harmonics of order 7 and 9 become significant |
| B. | harmonics of order 7 and 9 are eliminated |
| C. | harmonics of order 11 and 13 become significant |
| D. | harmonics of order 11 and 13 are eliminated |
| Answer» D. harmonics of order 11 and 13 are eliminated | |
| 8. |
In case of sinusoidal pulse width modulation with MI < 1, the order of the dominate harmonic can be raised by |
| A. | increasing the number of pulses |
| B. | reducing the number of pulses |
| C. | lowering the input voltage frequency |
| D. | raising the input voltage frequency |
| Answer» B. reducing the number of pulses | |
| 9. |
In case of sinusoidal pulse width modulation with MI < 1, if the number of pulses per half cycle (N) = 5, then |
| A. | harmonics of order 5 and 7 become significant |
| B. | harmonics of order 5 and 7 are eliminated |
| C. | harmonics of order 9 and 11 become significant |
| D. | harmonics of order 9 and 11 are eliminated |
| Answer» D. harmonics of order 9 and 11 are eliminated | |
| 10. |
In pulse width modulated inverters, the output voltage is controlled by controlling the |
| A. | input frequency |
| B. | modulating index |
| C. | amplification factor |
| D. | none of the mentioned |
| Answer» C. amplification factor | |