206. Double edge modulation eliminates certain harmonics when the reference is a__________?
A. Sine wave
B. Square wave
C. Triangular wave
D. Trapezoidal wave
207. Under harmonic free load voltages, the 3 phase VSI_____________?
A. Does not contains second harmonic
B. Does not contains third harmonic
C. Does not contains fifth harmonic
D. Does not contains seventh harmonic
208. In a three phase voltage source inverters____________?
A. Only amplitude of voltage is controllable
B. Only phase is controllable
C. Both amplitude and phase is controllable
D. Amplitude, phase and frequency of voltages should always be controllable
209. The square wave operation of 3 phase VSI lines contains the harmonics. The amplitudes are____________?
A. Directly proportional to their harmonic order
B. Inversely proportional to their harmonic order
C. Not related to their harmonic order
D. None of these
210. In a 3 phase VSI out of eight valid states, the number of valid states that produce zero ac line voltages is/are_________?
A. One
B. two
C. Three
D. Four
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211. In bipolar modulation, the carrier is symmetric about zero with amplitude equal to Cm, the PWM output
A. Zero
B. Switches between – 1 / 2 and + 1 / 2
C. Switches between – 1 and + 1
D. Switches between 0 and + 1
212. In the operation and control of both naturally commutated and forced commutated SCR base converter, commutation plays an important role. The converters is / are ___________?
A. AC – DC
B. DC – DC
C. DC – AC
D. All of these
213. Double fourier series analysis of PWM is_____________?
A. Two dimensional functions
B. Three dimensional functions
C. One dimensional functions
D. All of these
214. In commutation PAC stands for_______?
A. Permanent angle converter
B. Phase angle converter
C. Phase angle commutation
D. Phase and commutation
215. In single phase VSI, the harmonic which is not present is____________?
A. 2nd
B. 3rd
C. 5th
D. 7th
216. An ideal switch is___________?
A. Lossless
B. Carry current in any direction when it is on
C. Does not carry any current in any direction when it is off
D. All of these
217. Electrical power output in a d.c. generator is equal to____________?
A. Electrical power developed in armature – copper losses
B. Mechanical power input – iron and friction losses
C. Electrical power developed in armature – iron and copper losses
D. Mechanical power input – iron and friction losses – copper losses
218. IGBT stands for___________?
A. Insulated gate bipolar transistor
B. Insulated gate bidirectional transistor
C. Inductive gate bipolar transistor
D. Inductive gate bidirectional transistor
219. The switching function of semiconductor devices can be characterized with___________?
A. Duty ratio only
B. Frequency only
C. Duty ratio and frequency
D. Duty ratio, frequency and time delay
220. Number of PN junction in an SCR is____________?
A. Two
B. Three
C. Four
D. Five
NOTE
IF YOU THINK ANY OF THE MCQ ABOVE IS WRONG.
PLEASE COMMENT WITH CORRECT ANSWER AND ITS DETAIL EXPLANATION IN COMMENT BOX.
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