Power Electronics MCQ Multiple Choice Questions - Page 8 for Practice

Q: 106. Power electronics essentially deals with control of a.c. power at …………

Correct Answer is: 50 Hz frequency

Q: 107. Silicon controlled rectifier can be turned on

Correct Answer is: By applying a gate pulse and turned off only when current becomes zero

Q: 108. Single phase VSI are mainly used in

Correct Answer is: All of these

Q: 109. The advantage of using free – wheeling diode in half controlled bridge converter is that

Correct Answer is: There is always a path for the dc current independent of the ac line

Q: 110. The conduction losses in IGBT is

Correct Answer is: Lower than that of MOSFET

Q: 113. The effects of EMI can be reduced by

Correct Answer is: All of these

Q: 115. The most suited gate pulses given to the AC regulator with R – L load can be in the form of

Correct Answer is: A train of pulses

Q: 116. The normal way to turn on a diac is by ………………..

Correct Answer is: Breakover voltage

Q: 117. The output power of the cascaded amplifier-attenuator system can be determined using

Correct Answer is: Actual gain of amplifier and attenuator

Q: 118. The power MOSFET device is a

Correct Answer is: Current controlled unipolar device

Power Electronics MCQ Questions for Practice

106. Power electronics essentially deals with control of a.c. power at …………

Frequencies less than 10 Hz
Frequencies above 20 kHz
50 Hz frequency
Frequencies above 1000 kHz

107. Silicon controlled rectifier can be turned on

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

108. Single phase VSI are mainly used in

Multilevel configuration
Power supplies
All of these
Ups

109. The advantage of using free – wheeling diode in half controlled bridge converter is that

There is always a path for the dc current dependent of the ac line
There is always a path for the dc current independent of the ac line
There is always a path for the ac current independent of the ac line
There is always a path for the ac current independent of the ac line

110. The conduction losses in IGBT is

Equal to that of MOSFET
More than that of MOSFET
Equal to that of BJT
Lower than that of MOSFET

111. The device that does not have the gate terminal is ……………….

SCR
Triac
Diac
FET

112. The device that exhibits negative resistance region is ………………..

Transistor
Diac
UJT
Triac

113. The effects of EMI can be reduced by

Reducing the susceptibility of the receptor
Suppressing emissions
All of these
Reducing the efficiency of the coupling path

114. The input current waveform of a bridge controlled rectifier when the load is perfectly filtered is

Saw â€“ tooth wave
Sine wave
Trapezoidal wave
Square wave

115. The most suited gate pulses given to the AC regulator with R – L load can be in the form of

A train of pulses
Continuous signal
None of these
Large isolating pulse transformer

116. The normal way to turn on a diac is by ………………..

Breakover voltage
Gate current
None of the above
Gate voltage

117. The output power of the cascaded amplifier-attenuator system can be determined using

Gain in dB of amplifier and attenuator
Actual gain of amplifier
Actual gain of attenuator
Actual gain of amplifier and attenuator

118. The power MOSFET device is a

Current controlled bipolar device
Current controlled unipolar device
Voltage controlled bipolar device
Voltage controlled unipolar device

119. The square wave operation of 3 phase VSI lines contains the harmonics. The amplitudes are

Not related to their harmonic order
Directly proportional to their harmonic order
None of these
Inversely proportional to their harmonic order

120. The switching function of semiconductor devices can be characterized with

Duty ratio and frequency
Duty ratio only
Duty ratio, frequency and time delay
Frequency only