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## 15 MCQ's on Power Electronics|Power Electronics MCQ's

In this post,15 MCQ questions on Power Electronics is included. These questions will be helpful for the Electrical and Electronics Engineering aspirants of all technical competitive Exams. you can also visit EEE Notebook for more notes for Polytechnic Lecturer Electronics and Industries Extension officer. You can also get notes from My Notebook and Notebook(old EEE Made Easy). For video classes, visit EEE Made Easy youtube Channel

1) Silicon controlled rectifier can be turned on

a. By applying a gate pulse and turned off only when current becomes zero
b. And turned off by applying gate pulse
c. By applying a gate pulse and turned off by removing the gate pulse
d. By making current non zero and turned off by making current zero

2.TRIAC is a semiconductor power electronic device which contains
a. Two SCR’s connected in reverse parallel
b. Two SCR’s connected in parallel
c. Two SCR’s connected in series
d. Two BJT’s connected in series

3.An SCR can be used
a. as static conductor
b. for power control
c. for speed control of dc shunt motor
d. all of these

4.A crowbar is a circuit which is used to protect a
a. voltage sensitive load from excessive dc power supply output voltages
b. current sensitive load from excessive dc power supply output voltages
c. voltage sensitive load from excessive ac power supply output voltages

d. current sensitive load from excessive ac power supply output voltages

5.A full wave rectifier with resistive load produces
a. Second harmonic
b. Third harmonic
c. Fifth harmonic
d. Do not produce harmonics

6.The input current waveform of a bridge controlled rectifier when the load is perfectly
filtered is
a. Sine wave
b. Square wave
c. Saw - tooth wave

d. Trapezoidal wave

7.The advantage of using free - wheeling diode in half controlled bridge converter is that
a. There is always a path for the dc current independent of the ac line
b. There is always a path for the ac current independent of the ac line
c. There is always a path for the dc current dependent of the ac line
d. There is always a path for the ac current independent of the ac line

8.Harmonics in 3 phase inverters can be reduced by using
a. Passive filter
b. Active filter
c. Both passive and active filters
d. None of these

9.The most suited gate pulses given to the AC regulator with R - L load can be in the
form of
a. Continuous signal
b. Large isolating pulse transformer
c. A train of pulses
d. None of these

10.With increase in firing angle,
a. Both harmonic distortion and quality of input current increases
b. Harmonic distortion increases and quality of input current decreases
c. Harmonic distortion decreases and quality of input current increases
d. Both harmonic distortion and quality of input current decreases

11.The power MOSFET device is a
a. Current controlled unipolar device
b. Voltage controlled unipolar device
c. Current controlled bipolar device
d. Voltage controlled bipolar device

12.The conduction losses in IGBT is

a. More than that of MOSFET
b. Lower than that of MOSFET
c. Equal to that of MOSFET
d. Equal to that of BJT

13.For a buck converter to reduce the conduction losses in the diode

a. A high on-resistance switch can be added in parallel
b. A low on-resistance switch can be added in parallel
c. A high on-resistance switch can be added in series
d. A low on-resistance switch can be added in series

14.For the bidirectional operation of converters

a. A parallel combination of controllable switch and a diode is used
b. A parallel combination of controllable switch and capacitor is used
c. A series combination of controllable switch and a diode is used
d. A series combination of controllable switch and a capacitor is used

15. Single-phase VSI is mainly used in

a. Power supplies
b. Ups
c. Multilevel configuration
d. All of these

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