Electrical Engineering Mcqs

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

Submitted By: Ali Uppal


Double edge modulation eliminates certain harmonics when the reference is a__________?

(A) Sine wave

(B) Square wave

(C) Triangular wave

(D) Trapezoidal wave

Submitted By: Ali Uppal


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

Submitted By: Ali Uppal


For a buck converter to reduce the conduction losses in 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

Submitted By: Ali Uppal


Advantages of HVDC transmission over AC system is / are____________?

(A) Reversal of power can be controlled by firing angle

(B) Very good dynamic behavior

(C) They can link two AC system operating unsynchronized

(D) All of these

Submitted By: Ali Uppal


For 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

Submitted By: Ali Uppal


In rectifiers, load current flow is_________?

(A) Unidirectional

(B) Bidirectional

(C) Either (a) or (b)

(D) Non directional

Submitted By: Ali Uppal


Due to non sinusoidal waveform of the input current, the power factor of the rectifier is____________?

(A) Negatively affected by firing angle

(B) Negatively affected by distortion of the input current

(C) Positively affected by both firing angle and distortion of the input current

(D) Both (a) and (b)

Submitted By: Ali Uppal


Single phase VSI are mainly used in___________?

(A) Power supplies

(B) Ups

(C) Multilevel configuration

(D) All of these

Submitted By: Ali Uppal


The man made noise sources is / are_____________?

(A) Motors

(B) Switches, radio interferences

(C) Computers, digital electronics

(D) All of these

Submitted By: Ali Uppal