MCQOPTIONS
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MCQOPTIONS
This section includes 17 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 three phase half-wave cycloconverter ___________ |
| A. | both inverting and converting action takes place |
| B. | only inversion action takes place |
| C. | only converting action takes place |
| D. | none of the mentioned |
| Answer» B. only inversion action takes place | |
| 2. |
In three phase cycloconverters, the reduction factor is given by |
| A. | input frequency/output frequency |
| B. | (input frequency/output frequency) -1 |
| C. | (input frequency/output frequency) -1/2 |
| D. | (input frequency/output frequency) 1/2 |
| Answer» C. (input frequency/output frequency) -1/2 | |
| 3. |
The principle of three phase cycloconverter is to |
| A. | add and remove number of SCRs |
| B. | vary progressively the firing angle of the devices |
| C. | keep the firing angle as 0° for all the devices |
| D. | none of the mentioned |
| Answer» C. keep the firing angle as 0° for all the devices | |
| 4. |
In the positive half cycle, _________ SCRs are forward biased. |
| A. | P1, P2, N1, N2 |
| B. | P1, P2, P3, P4 |
| C. | N1, N2, N3, N4 |
| D. | P3, P4, N1, N2 |
| Answer» B. P1, P2, P3, P4 | |
| 5. |
In the below given cycloconverter circuit, _________ and _________ conduct in one cycle together. |
| A. | P1, P2 and N1, N2 |
| B. | P1, N2 and N1, P2 |
| C. | N1, P1 and N1, P2 |
| D. | None of the mentioned |
| Answer» C. N1, P1 and N1, P2 | |
| 6. |
In the positive half cycle from ωt = 0 to π |
| A. | P1 and P2 are forward biased |
| B. | N1 and P2 are forward biased |
| C. | P1 and N2 are forward biased |
| D. | None of the mentioned |
| Answer» D. None of the mentioned | |
| 7. |
The single phase bridge type cycloconverter uses __________ number of SCRs. |
| A. | 4 |
| B. | 8 |
| C. | 6 |
| D. | none of the mentioned |
| Answer» C. 6 | |
| 8. |
For a cycloconverter, when the displacement angle of the load is 0 degrees,each converter carries the load current when it operates in: |
| A. | its rectifying region only |
| B. | its rectifying and inverting region |
| C. | its inverting region only |
| D. | idle region only |
| Answer» B. its rectifying and inverting region | |
| 9. |
In a single-phase to single-phase cyclo-converter, the magnitudes of harmonic components are quite large. How can they be reduced? |
| A. | By using a chopper circuit |
| B. | By using an RC oscillator |
| C. | By using a three phase input supply |
| D. | By adding an alternator to the input |
| Answer» D. By adding an alternator to the input | |
| 10. |
An inter-group reactor is used in a single phase cyclo-converter circuit to |
| A. | reduce current ripples |
| B. | reduce voltage ripples |
| C. | limit circulating current |
| D. | limit di/dt in the semiconductor switch |
| Answer» D. limit di/dt in the semiconductor switch | |
| 11. |
Cyclo-converter converts: |
| A. | AC to DC |
| B. | DC to AC |
| C. | A fixed AC to a variable magnitude AC |
| D. | A fixed DC to a variable magnitude DC |
| Answer» D. A fixed DC to a variable magnitude DC | |
| 12. |
IN_THREE_PHASE_CYCLOCONVERTERS,_THE_REDUCTION_FACTOR_IS_GIVEN_BY?$ |
| A. | input frequency/output frequency |
| B. | (input frequency/output frequency) <sup>-1</sup> |
| C. | (input frequency/output frequency) <sup>-1/2</sup> |
| D. | (input frequency/output frequency) <sup>1/2</sup> |
| Answer» C. (input frequency/output frequency) <sup>-1/2</sup> | |
| 13. |
In_a_three_phase_half-wave_cycloconverter____________$ |
| A. | both inverting and converting action takes place |
| B. | only inversion action takes place |
| C. | only converting action takes place |
| D. | none of the mentioned |
| Answer» B. only inversion action takes place | |
| 14. |
The principle of three phase cycloconverter is t? |
| A. | add and remove number of SCRs |
| B. | vary progressively the firing angle of the devices |
| C. | keep the firing angle as 0° for all the devices |
| D. | none of the mentioned |
| Answer» C. keep the firing angle as 0¬¨¬®‚Äö√†√ª for all the devices | |
| 15. |
The single phase mid-point type cycloconverter uses __________ number of SCRs. |
| A. | 4 |
| B. | 8 |
| C. | 6 |
| D. | none of the mentioned |
| Answer» B. 8 | |
| 16. |
Applications of cycloconverters include |
| A. | speed control of ac drives |
| B. | induction heating |
| C. | static VAr compensation |
| D. | all of the mentioned |
| Answer» E. | |
| 17. |
A cycloconverter is a _________ |
| A. | one stage power converter |
| B. | one stage voltage converter |
| C. | one stage frequency converter |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |