Three Phase Full Wave Controlled Rectifier with Resistive Load MCQ [Free PDF] – Objective Question Answer for Three Phase Full Wave Controlled Rectifier with Resistive Load Quiz
21. What is the formula for output voltage for Boost converter?
A. 8D×Vin
B. 5D×Vin
C. 2D×Vin
D. D×Vin
Answer: D
The output voltage of the boost converter is Vo = Vin ÷ (1-D. The value of the duty cycle is less than one which makes the Vo > Vin. The boost converter is used to step up the voltage. Vin is a fixed voltage and Vo is a variable voltage.
22. ____________ is the boundary for C.C.M and D.C.M mode in 3-Φ Half wave bridge rectifier for R load.
A. 60°
B. 10°
C. 80°
D. 30°
Answer: D
30° is the boundary for C.C.M and D.C.M mode in 3-Φ Half wave bridge rectifier for R load. Conduction will only remain from 30°+α to 150°+α.
23. Buck-Boost acts as Buck converter for duty cycle is equal to _________
A. .9
B. .7
C. .6
D. .4
Answer: D
The output voltage of the buck-boost converter is Vo = D×Vin ÷ (1-D). It can step up and step down the voltage depending upon the value of the duty cycle.
If the value of the duty cycle is less than .5 it will work as a buck converter. The answer is .4.
24. Buck-Boost acts as Boost converter for duty cycle is equal to _________
A. .8
B. .1
C. .2
D. .4
Answer: A
The output voltage of the buck-boost converter is Vo = D×Vin ÷ (1-D). It can step up and step down the voltage depending upon the value of the duty cycle.
If the value of the duty cycle is more than .5 it will work as a boost converter. The answer is .8.
25. Inductor and Capacitor in Buck converter are used to ___________
A. Increase the cost
B. Decrease the cost
C. Filter out the harmonics
D. Increase the harmonics
Answer: C
Inductor and capacitor in Buck converter are used to filter out the harmonics. They remove the ripple from the output voltage.
26. Calculate peak-peak voltage if Vmax=1 V and Vmin=-1 V.
A. 6 V
B. 2 V
C. 3 V
D. 1 V
Answer: B
Peak-Peak voltage is equal to the difference between the maximum and minimum voltage. It is mathematically represented as
Vp-p=Vmax-Vmin=1+1=2 V.
27. Calculate the value of the Crest factor if Vpeak=0 V and Vr.m.s=24 V.
A. 0
B. 3
C. 5
D. 8
Answer: A
The value of the crest factor is Vpeak÷Vr.m.s=0÷24=0 V. It signifies the peak value is 0 times the r.m.s value.
28. Calculate the output voltage of the Buck converter if the supply voltage is 789 V and the duty cycle value is .9.
A. 711.1 V
B. 710.1 V
C. 722.2 V
D. 713.2 V
Answer: B
The output voltage of the buck converter is
Vo = Vin×D =789×.9=710.1 V.
The value of the duty cycle is less than one which makes the Vo < Vin. The buck converter is used to step down the voltage.
29. Calculate the average value of thyristor current in a 3-Φ Full-wave converter for the load current=27 A and α=6°.
A. 9 A
B. 4 A
C. 5 A
D. 9 A
Answer: D
The average value of thyristor current in a 3-Φ Full-wave converter is Io÷3. It is the average value of the thyristor current.
I(r.m.s)= Io÷3=9 A.
30. Calculate the output voltage of the Boost converter if the supply voltage is 156 V and the duty cycle value is .4.
A. 260 V
B. 264 V
C. 261 V
D. 268 V
Answer: A
The output voltage of the boost converter is
Vo = Vin×(1-D).=156×1.66=260 V.
The value of the duty cycle is less than one which makes the Vo > Vin. The boost converter is used to step up the voltage.
