Top 250+ Solved Power Electronics MCQ Questions Answer
Q. Form factor of a rectifier is the ratio of
a. Root mean square value of voltage and current to its peak value
b. Root mean square value of voltage and current to its average value
c. Average value of current and voltage to its root mean square value
d. Peak value of current and voltage to its root mean square value
Q. Ripple factor is the ratio of
a. Rms value of the ac component of load voltage to the dc voltage
b. Average value of the ac component of load voltage to the peak value of voltage
c. Average value of the dc component of load voltage to the ac voltage
d. Peak value of the dc component of load voltage to the ac voltage
Q. Transformer utilization factor is a measure of the merit of a rectifier circuit.It is the ratio of
a. AC input power to the transformer volt - amp rating required by secondary
b. AC input power to the transformer volt - amp rating required by primary
c. DC output power to the transformer volt - amp rating required by secondary
d. DC output power to the transformer volt - amp rating required by primary
Q. Which of the following finds application in speed control of a dc motor?
a. FET
b. NPN transistor.
c. SCR.
d. None of the above.
Q. In mercury arc rectifiers the voltage drop in arc is nearly
a. 0.1 volt per centimeter of arc length
b. 1 volt per centimeter of arc length
c. 10 volts per centimeter of arc length
d. 12 to 15 volts per centimeter of arc length.
Q. A cycloconverter is a _________
a. one stage power converter
b. one stage voltage converter
c. one stage frequency converter
d. none of the mentioned
Q. Applications of cycloconverters include
a. speed control of ac drives
b. induction heating
c. static VAr compensation
d. all of the mentioned
Q. The single phase mid-point type cycloconverter uses __________ number ofSCRs.
a. 4
b. 8
c. 6
d. none of the mentioned
Q. The single phase bridge type cycloconverter uses __________ number ofSCRs.
a. 4
b. 8
c. 6
d. none of the mentioned
Q. 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
Q. 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/
Q. 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
Q. In the ___________ type of chopper, two stage conversions takes place.
a. AC-DC
b. AC link
c. DC link
d. None of the mentioned
Q. A chopper may be thought as a
a. Inverter with DC input
b. DC equivalent of an AC transformer
c. Diode rectifier
d. DC equivalent of an induction motor