Power Electronics MCQ Multiple Choice Questions - Page 7 for Practice
Power Electronics MCQ Questions for Practice
91. For a buck converter to reduce the conduction losses in diode
Correct Answer is: A low on – resistance switch can be added in parallel
92. For bidirectional operation of converters
Correct Answer is: A parallel combination of controllable switch and a diode is used
93. For similar carrier and modulating signals, the line current used in CSI is
Correct Answer is: Identical to line voltage in a VSI
94. For sweptfrequency measurements, the input impedance of the mismatched transmission line would vary with frequency as the electrical length ofthe transmission line would
Correct Answer is: Increase with frequency
95. Harmonics in 3 phase inverters can be reduced by using
Correct Answer is: Both passive and active filters
96. In a 3 phaseCSI, if the required line output voltages are balanced and 120 degreeout of phase, then the chopping angles are used to eliminate only theharmonics at frequencies
Correct Answer is: All of these
97. In a load commutated DC – DC chopper, the capacitor has a
Correct Answer is: Symmetric trapezoidal voltage across itself
98. In a three phase converter, the number of notches per cycle is
Correct Answer is: Six
99. In a UJT, the p-type emitter is ……………. doped
Correct Answer is: Heavily
100. In bipolar modulation, the carrier is symmetric about zero with amplitude equal to Cm, the PWM output
Correct Answer is: Switches between – 1 / 2 and + 1 / 2
101. In current commutated DC-DC choppers, the voltage spike appears across the load when
Correct Answer is: Both (a and b)
102. In EMCsignal, the source delivers maximum power to the input of transmissionline when the transmission line input impedance
Correct Answer is: Is equal to the source resistance
103. In radiative coupling, the emitter radiation field
Correct Answer is: Decays as 1 / 2 R, where R is the separation distance between the emitter and the receptor
104. In single phase VSI, the harmonic which is not present is
Correct Answer is: 2nd
105. LISN is a device used to measure conducted emissions. LISN stands for
Correct Answer is: Line impedance stabilization network
