Explore topic-wise MCQs in Power Electronics.

This section includes 4 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.

SCRs with a rating of 1000 V & 200 A are available to be used in a string to handle 6 KV & 1 KV. Calculate the number of series & parallel units required in case the de-rating factor is 0.1. (Round off the fraction to the greatest & nearest integer)

A. Series = 7, Parallel = 6
B. Series = 6, Parallel = 7
C. Series = 6, Parallel = 6
D. Series = 7, Parallel = 7
Answer» B. Series = 6, Parallel = 7
Discussion
2.

Two parallel connect SCRs have same voltage drop (Vt) having rated current = 2I1. SCR-1 carries a current of I1=2.6 A whereas SCR-2 carries a current of I2=1.4 A. Find the string efficiency.

A. 45 %
B. 77 %
C. 92 %
D. 84 %
Answer» C. 92 %
Discussion
3.

3 SCRs are connected in series. The string efficiency is 91%. SCRs 1, 2 & 3 have leakage currents 4 mA, 8 mA & 12 mA. Which SCR will block more voltage?

A. SCR-1
B. SCR-2
C. SCR-3
D. All the three will block equal voltage
Answer» B. SCR-2
Discussion
4.

The term used to measure the degree of utilization of SCRs connected in series & parallel is

A. tuf
B. string efficiency
C. voltage/current utilization ratio
D. rectification efficiency
Answer» C. voltage/current utilization ratio
Discussion