# DC Motor Systems MCQ Questions & Answers

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

Question 1

Calculate the average value of the current through the thyristor in case of 1-? Full wave bridge rectifier if the value of the load current is 42 A.

A. 21 A
B. 12 A
C. 14 A
D. 16 A

Question 2

Calculate the conduction angle in purely inductive load if the firing angle is ?÷2.

A. 205°
B. 175°
C. 180°
D. 195°

Question 3

Calculate the displacement factor if the fundamental voltage is 24sin(140?t-240°) and fundamental current is 47sin(140?t-120°).

A. -0.5
B. -0.7
C. 0.9
D. 0.4

Question 4

Calculate the extinction angle in purely inductive load if the firing angle is ?÷4.

A. 315°
B. 145°
C. 345°
D. 285°

Question 5

Calculate the PIV for the Mid-point configuration of Full-wave rectifier if the peak value of the supply voltage is 311.

A. 622 V
B. 620 V
C. 624 V
D. 626 V

Question 6

Calculate the r.m.s value of the current through the thyristor in case of 1-? Full wave bridge rectifier if the value of the load current is 2 A.

A. 1.414 A
B. 1.214 A
C. 1.347 A
D. 1.657 A

Question 7

Calculate the value of THD value for 1-? Full wave bridge rectifier.

A. 48.43 %
B. 47.25 %
C. 49.26 %
D. 50.48 %

Question 8

Calculate the value of the fundamental displacement factor for 1-? Full wave bridge rectifier if the firing angle value is 60°.

A. 0.5
B. 0.4
C. 0.2
D. 0.8

Question 9

Calculate the value of the fundamental displacement factor for 1-? Full wave semi-converter if the firing angle value is 20°.

A. 0.82
B. 0.98
C. 0.74
D. 0.26

Question 10

Calculate the value of the Input power factor for 1-? Full wave bridge rectifier if the firing angle value is 45°.

A. 0.65
B. 0.64
C. 0.61
D. 0.63

Question 11

In Half-wave controlled rectifier calculate the average value of the voltage if the supply is 10sin(50t) and firing angle is 30°.

A. 2.32 V
B. 2.97 V
C. 4.26 V
D. 5.64 V

Question 12

In Half-wave uncontrolled rectifier calculate the average value of the voltage if the supply is 23sin(50t).

A. 7.32 V
B. 8.32 V
C. 9.32 V
D. 7.60 V

Question 13

In single phase RLE load, calculate the voltage across the thyristor when current decays to zero using the data: (Vs)r.m.s=220 V, f=40 Hz, R=1 ?, E=90 V, ?=230°.

A. -328.33 V
B. -325.48 V
C. -254.85 V
D. -284.48 V

Question 14

A. True
B. False

Question 15

A. True
B. False

Question 16

Calculate the average value of the current through the thyristor in case of 1-Φ Full wave bridge rectifier if the value of the load current is 42 A.

A. 21 A
B. 12:00 AM
C. 14 A
D. 16 A

Question 17

Calculate the conduction angle in purely inductive load if the firing angle is π÷2.

A. 205°
B. 175°
C. 180°
D. 195°

Question 18

Calculate the displacement factor if the fundamental voltage is 24sin(140πt-240°) and fundamental current is 47sin(140πt-120°).

A. -0.5
B. -0.7
C. 0.9
D. 0.4

Question 19

Calculate the extinction angle in purely inductive load if the firing angle is π÷4.

A. 315°
B. 145°
C. 345°
D. 285°

Question 20

Calculate the r.m.s value of the current through the thyristor in case of 1-Φ Full wave bridge rectifier if the value of the load current is 2 A.

A. 1.414 A
B. 1.214 A
C. 1.347 A
D. 1.657 A

Question 21

Calculate the value of THD value for 1-Φ Full wave bridge rectifier.

A. 48.43%
B. 47.25%
C. 49.26%
D. 50.48%

Question 22

Calculate the value of the fundamental displacement factor for 1-Φ Full wave bridge rectifier if the firing angle value is 60°.

A. 0.5
B. 0.4
C. 0.2
D. 0.8

Question 23

Calculate the value of the fundamental displacement factor for 1-Φ Full wave semi-converter if the firing angle value is 20°.

A. 0.82
B. 0.98
C. 0.74
D. 0.26

Question 24

Calculate the value of the Input power factor for 1-Φ Full wave bridge rectifier if the firing angle value is 45°.

A. 0.65
B. 0.64
C. 0.61
D. 0.63