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.

IN_A_3-PHASE_SEMI-CONVERTER,_FOR_FIRING_ANGLE_LESS_THAN_60¬¨ àû_THE_FREEWHEELING_DIODE_CONDUCTS_FOR?$#

A. 30°
B. 60°
C. 120°
D. 0
Answer» E.
Discussion
2.

A three-phase semi-converter circuit is given a supply of 400 V. It produces at the output terminals an average voltage of 381 V. Find the rectification efficiency of the converter circuit?

A. 99.65 %
B. 95.25 %
C. 91 %
D. 86.5 %
Answer» C. 91 %
Discussion
3.

A 3-phase full converter feeds power to an R load of 10 Ω. For a firing angle delay of 30° the load takes 5 kW. An inductor of large value is also connected to the load to make the current ripple free. Find the value of per phase input voltage?#

A. 133 V
B. 230/‚àö3 V
C. 191/‚àö3 V
D. 298/‚àö3 V
Answer» D. 298/‚Äö√Ñ√∂‚àö‚Ć‚àö‚àÇ3 V
Discussion
4.

A three-phase full converter is driving a DC motor. If a continues current of Im amperes is flowing through the motor load, then find the rms value of supply current drawn by the converter to drive the motor.

A. Im/‚àö2
B. Im<sup>2</sup>/3
C. ‚àö2Im/‚àö3
D. ‚àö2Im/3
Answer» D. ‚Äö√Ñ√∂‚àö‚Ć‚àö‚àÇ2Im/3
Discussion
5.

A three-phase full converter supplied from a 230 V source is working as a line commutated inverter. The load consists of RLE type with R = 5 Ω, E = 200 V and L = 1 mH. A continues current of 10 A is flowing through the load, find the value of the firing angle delay.

A. 119°
B. 127°
C. 156°
D. 143°
Answer» B. 127¬¨¬®‚Äö√†√ª
Discussion