# AC Motor Systems MCQ Questions & Answers

AC Motor Systems MCQs : This section focuses on the "AC Motor Systems". These Multiple Choice Questions (MCQs) should be practiced to improve the AC Motor Systems skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

Calculate peak-peak voltage if Vmax=80 V and Vmin=20 V.

A. 60 V
B. 50 V
C. 70 V
D. 10 V

Question 2

Calculate the circuit turn-off time for 3-? Fully controlled rectifier if the firing angle is 110° and supply frequency is 50 Hz.

A. 3.8 msec
B. 5.2 msec
C. 9.3 msec
D. 8.7 msec

Question 3

Calculate the circuit turn-off time for 3-? Fully controlled rectifier if the firing angle is 20° and supply frequency is 60 Hz.

A. 8.8 msec
B. 7.4 msec
C. 10.1 msec
D. 6.5 msec

Question 4

Calculate the output frequency for the two-pulse converter if the supply frequency is 20 Hz.

A. 40 Hz
B. 20 Hz
C. 60 Hz
D. 90 Hz

Question 5

Calculate the output voltage of the Boost converter if the supply voltage is 8 V and duty cycle value is .6.

A. 40 V
B. 20 V
C. 48 V
D. 51 V

Question 6

Calculate the output voltage of the Buck converter if the supply voltage is 11 V and duty cycle value is .4.

A. 4.4 V
B. 2.2 V
C. 4.8 V
D. 6.4 V

Question 7

Calculate the output voltage of the Buck-Boost converter if the supply voltage is 78 V and duty cycle value is .1.

A. 7.2 V
B. 4.5 V
C. 8.6 V
D. 5.1 V

Question 8

Calculate the pulse number if the supply frequency is 2? and the output frequency is ?÷3.

A. 4
B. 2
C. 6
D. 8

Question 9

Calculate the value of Crest factor if Vpeak=12 V and Vr.m.s=24 V.

A. 0.2
B. 0.3
C. 0.4
D. 0.5

Question 10

Calculate the value of THD value for 3-? Fully controlled rectifier.

A. 48.43 %
B. 47.25 %
C. 39.26 %
D. 31 %

Question 11

Calculate the value of the Input power factor for 3-? Fully controlled rectifier if the firing angle value is 70°.

A. 0.32
B. 0.38
C. 0.31
D. 0.33

Question 12

In 3-? Fully controlled rectifier calculate the average value of the voltage if the supply is 400 V and firing angle is 15°.

A. 521.2 V
B. 522 V
C. 523 V
D. 524 V

Question 13

In 3-? Semi-controlled rectifier calculate the average value of the voltage if the supply is 440 V and firing angle is 22°.

A. 571.5 V
B. 572.8 V
C. 548.3 V
D. 524.1 V

Question 14

The principle of Boost converter can be applied for the regenerative braking.

A. True
B. False

Question 15

The unit of angular acceleration is Joule.

A. True
B. False

Question 16

Calculate the circuit turn-off time for 3-Φ Fully controlled rectifier if the firing angle is 20° and supply frequency is 60 Hz.

A. 8.8 msec
B. 7.4 msec
C. 10.1 msec
D. 6.5 msec

Question 17

Calculate the pulse number if the supply frequency is 2π and the output frequency is π÷3.

A. 4
B. 2
C. 6
D. 8

Question 18

Calculate the value of THD value for 3-Φ Fully controlled rectifier.

A. 48.43%
B. 47.25%
C. 39.26%
D. 31%

Question 19

Calculate the value of the Input power factor for 3-Φ Fully controlled rectifier if the firing angle value is 70°.

A. 0.32
B. 0.38
C. 0.31
D. 0.33

Question 20

In 3-Φ Fully controlled rectifier calculate the average value of the voltage if the supply is 400 V and firing angle is 15°.

A. 521.2 V
B. 522 V
C. 523 V
D. 524 V