MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 16 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. |
The thermal resistance between junction & the SCR (θjc) has the unit |
| A. | Ω/°C |
| B. | W/Ω |
| C. | has the unita) Ω/°Cb) W/Ωc) °C/W |
| D. | ΩW/°C |
| Answer» D. ΩW/°C | |
| 2. |
The maximum rms current of an SCR is 50 A. For a 120° sine wave conduction the form factor (FF) = 1.878Find the average on-state current rating (ITAV). |
| A. | 93.9 A |
| B. | 174 A |
| C. | 26.62 A |
| D. | 68.52 A |
| Answer» D. 68.52 A | |
| 3. |
The amp2-sec rating of the SCR specifies |
| A. | The power dissipated by the device when fault occurs |
| B. | The energy dissipated by the device when fault occurs |
| C. | The energy that the device can absorb before the fault is cleared |
| D. | The energy that the device can absorb while operating in the forward blocking mode. |
| Answer» D. The energy that the device can absorb while operating in the forward blocking mode. | |
| 4. |
For an SCR the average & rms values of current are I/4 & I/2 respectively. Calculate the average on-state current rating (ITAV). Take maximum RMS on-state current = 35 A. |
| A. | 8.78 A |
| B. | 10.10 A |
| C. | 17.5 A |
| D. | 24.74 A |
| Answer» D. 24.74 A | |
| 5. |
For a SCR the maximum rms on-state current is 35 A. If the SCR is used in a resistive circuit for a rectangular wave with conduction angle of 90°. Calculate the average & rms currents respectively. |
| A. | I/4, I/2 |
| B. | I/2, I/√2 |
| C. | I/4, I2/2 |
| D. | I/4, I/√2 |
| Answer» B. I/2, I/√2 | |
| 6. |
The voltage safety factor (VSF) for an SCR is the ratio of |
| A. | peak working voltage & peak reverse repetitive voltage |
| B. | dv/dt & di/dt |
| C. | peak repetitive reverse voltage & maximum value of input voltage |
| D. | peak repetitive reverse voltage & rms value of input voltage |
| Answer» D. peak repetitive reverse voltage & rms value of input voltage | |
| 7. |
THE_THERMAL_RESISTANCE_BETWEEN_JUNCTION_&_THE_SCR_(‚ÂÀ√≠‚ÄÖ√†√®JC)_HAS_THE_UNIT?$# |
| A. | Ω/°C |
| B. | W/Ω |
| C. | °C/W |
| D. | ΩW/°C |
| Answer» D. ‚Äö√Ñ√∂‚àö√´¬¨‚àÇW/¬¨¬®‚Äö√†√ªC | |
| 8. |
THE_MAXIMUM_RMS_CURRENT_OF_AN_SCR_IS_50_A._FOR_A_120¬¨ àû_SINE_WAVE_CONDUCTION_THE_FORM_FACTOR_(FF)_=_1.878?$# |
| A. | . |
| B. | 93.9 A |
| C. | 174 A |
| D. | 26.62 A |
| Answer» D. 26.62 A | |
| 9. |
The amp2-sec rating of the SCR specifie? |
| A. | The power dissipated by the device when fault occurs |
| B. | The energy dissipated by the device when fault occurs |
| C. | The energy that the device can absorb before the fault is cleared |
| D. | The energy that the device can absorb while operating in the forward blocking mode. |
| Answer» D. The energy that the device can absorb while operating in the forward blocking mode. | |
| 10. |
For an SCR the average & rms values of current are I/4 & I/2 respectively. Calculate the average on-state current rating (ITAV). Take maximum RMS on-state current = 35 A. |
| A. | 8.78 A |
| B. | 10.10 A |
| C. | 17.5 A |
| D. | 24.74 A |
| Answer» D. 24.74 A | |
| 11. |
For a SCR the maximum rms on-state current is 35 A. If the SCR is used in a resistive circuit for a rectangular wave with conduction angle of 90°. Calculate the average & rms currents respectively.$ |
| A. | I/4, I/2 |
| B. | I/2, I/‚àö2 |
| C. | I/4, I<sup>2</sup>/2 |
| D. | I/4, I/‚àö2 |
| Answer» B. I/2, I/‚Äö√Ñ√∂‚àö‚Ć‚àö‚àÇ2 | |
| 12. |
An SCR has half cycle surge current rating of 3000 A for 50 Hz. Calculate its one-cycle surge current rating |
| A. | 3121.32 A |
| B. | 2121.32 A |
| C. | 3131.32 A |
| D. | 2131.32 A |
| Answer» C. 3131.32 A | |
| 13. |
Which among the following anode current waveforms will have the minimum junction temperature? |
| A. | 100 % DC |
| B. | 25 % DC |
| C. | 50 % DC |
| D. | AC |
| Answer» C. 50 % DC | |
| 14. |
The finger voltage of an SCR is |
| A. | minimum value of Vak to turn on the device with gate triggering |
| B. | maximum value of Vak to turn on the device with gate triggering |
| C. | minimum value of Vak to turn on the device without gate triggering |
| D. | maximum value of Vak to turn on the device without gate triggering |
| Answer» B. maximum value of Vak to turn on the device with gate triggering | |
| 15. |
The forward dv/dt rating of an SCR |
| A. | increases with increase in the junction temperature |
| B. | decreases with increase in the junction temperature |
| C. | increases with decrease in the rms value of forward anode-cathode voltage |
| D. | decreases with decrease in the rms value of forward anode-cathode voltage |
| Answer» B. decreases with increase in the junction temperature | |
| 16. |
The voltage safety factor (VSF) for an SCR is the ratio of |
| A. | peak working voltage & peak reverse repetitive voltage |
| B. | dv/dt & di/dt |
| C. | peak repetitive reverse voltage & maximum value of input voltage |
| D. | peak repetitive reverse voltage & rms value of input voltage |
| Answer» D. peak repetitive reverse voltage & rms value of input voltage | |