MCQOPTIONS
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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. |
The area under the curve of the gate characteristics of thyristor gives the |
| A. | total average gate current |
| B. | total average gate voltage |
| C. | total average gate impedance |
| D. | total average gate power dissipation |
| Answer» E. | |
| 2. |
The gate characteristics of thyristor is a plot of |
| A. | Vg on the X-axis & Ig on the Y-axis |
| B. | Ig on the X-axis & Vg on the Y-axis |
| C. | Va on the X-axis & Ig on the Y-axis |
| D. | Ig on the X-axis & Va on the Y-axis |
| Answer» C. Va on the X-axis & Ig on the Y-axis | |
| 3. |
To avoid commutation failure |
| A. | circuit turn-off time must be greater than the thyristor turn-off time |
| B. | circuit turn-off time must be lesser than the thyristor turn-off time |
| C. | circuit turn-off time must be equal to the thyristor turn-off time |
| D. | none of the above mentioned |
| Answer» B. circuit turn-off time must be lesser than the thyristor turn-off time | |
| 4. |
For effective turning off of the SCR after the anode current has reached zero value, ______________ |
| A. | chargers are injected by applying reverse anode-cathode voltage |
| B. | chargers are removed by applying reverse anode-cathode voltage |
| C. | chargers are injected by applying gate signal |
| D. | chargers are removed by applying gate signal |
| Answer» C. chargers are injected by applying gate signal | |
| 5. |
For an SCR the total turn-on time consists ofi) Delay timeii) Rise time and theiii) Spread timeThe spread time interval depends upon |
| A. | the value of gate current |
| B. | junction temperature |
| C. | area of the cathode |
| D. | area of the anode |
| Answer» D. area of the anode | |
| 6. |
The latching current is _________ than the holding current |
| A. | lower |
| B. | higher |
| C. | same as |
| D. | negative of |
| Answer» C. same as | |
| 7. |
For an SCR the total turn-on time consists ofi) Delay timeii) Rise time andiii) Spread timeDuring the rise time the |
| A. | anode current flows only near the gate |
| B. | anode current rises from zero to very high value |
| C. | losses are maximum |
| D. | anode to cathode voltage is zero |
| Answer» D. anode to cathode voltage is zero | |
| 8. |
The minimum value of anode current below which it must fall to completely turn-off the device is called as the |
| A. | holding current value |
| B. | latching current value |
| C. | switching current value |
| D. | peak anode current value |
| Answer» B. latching current value | |
| 9. |
For an SCR the total turn-on time consists ofi) Delay timeii) Rise time andiii) Spread timeDuring the delay time the |
| A. | anode current flows only near the gate |
| B. | anode current rises from zero to very high value |
| C. | losses are maximum |
| D. | anode to cathode voltage is zero |
| Answer» B. anode current rises from zero to very high value | |
| 10. |
During the transition time or turn-on time |
| A. | The forward anode voltage decreases from 90 % to 10 % & the anode current also decreases from 90 to 10 % of the initial value |
| B. | The forward anode voltage increases from 10 % to 90 % & the anode current also increases from 10 % to 90 % of the initial value |
| C. | The forward anode voltage decreases from 90 % to 10 % & the anode current increases from 10 % to 90 % of the initial value |
| D. | The forward anode voltage increases from 10 % to 90 % & the anode current decreases from 90% to 10% of the initial value |
| Answer» D. The forward anode voltage increases from 10 % to 90 % & the anode current decreases from 90% to 10% of the initial value | |