Explore topic-wise MCQs in Power Electronics.

This section includes 5 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.

A three-phase half-wave controlled converter is fed from a 3-phase, 400 V source and is connected to a load which takes a constant current of 36 A. Find, the value of average output voltage and average current rating of SCR for a firing angle of 30 .

A. 234 V, 36 A
B. 234 V, 12 A
C. 135 V, 36 A
D. 135 V, 12 A
Answer» C. 135 V, 36 A
Discussion
2.

A three-phase M-3 converter is operated from a 3-phase, 230 V, 50 Hz supply with load resistance R = 10 . Find the value of firing angle if an average output voltage of 50% of the maximum possible output voltage is required.Hint: > 30 .

A. 92.7
B. 67.7
C. 45
D. 75.7
Answer» C. 45
Discussion
3.

A three-phase three pulse type controlled converter is constructed using 3 SCR devices. The circuit is supplying an R load with < 30 . As such, each SCR device would conduct for

A. 60 each cycle
B. 120 each cycle
C. 180 each cycle
D. 360 each cycle
Answer» C. 180 each cycle
Discussion
4.

In a three-phase, three-pulse, M-3 type controlled converter T1 starts to conduct at 30 + n . At what angles do T2 and T3 start to conduct? Assume that the conduction sequence is T1-T2-T3.

A. 2n and 3n
B. 150 + n and 270 + n
C. n each
D. 30 + n and 60 + n
Answer» C. n each
Discussion
5.

A three-phase, three-pulse, M-3 type controlled converter has firing angle for one of the SCRs set as 15 . This SCR would start conducting at

A. 0
B. 15
C. 30
D. 45
Answer» E.
Discussion