# Series Motor Speed MCQ Questions & Answers

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

Question 1

A 38-pole, 3-phase, 80 Hz induction motor is operating at a speed of 12 rpm. The frequency of the rotor current of the motor in Hz is __________

A. 75.2
B. 76.1
C. 79.2
D. 79.6

Question 2

A 3-phase induction motor runs at almost 70 rpm at no load and 50 rpm at full load when supplied with power from a 50 Hz, 3-phase supply. What is the corresponding speed of the rotor field with respect to the rotor?

A. 20 revolution per minute
B. 30 revolution per minute
C. 40 revolution per minute
D. 50 revolution per minute

Question 3

A particular current is made up of two components: a 10 A and a sine wave of peak value 14.14 A. The average value of current is _________

A. Zero
B. 24.14 A
C. 10 A
D. 14.14 A

Question 4

A particular voltage is made up of two components: a 5 A and a cosine wave of peak value 7.8 A. The average value of voltage is _________

A. Zero
B. 35.14 A
C. 78 A
D. 5 A

Question 5

Armature reaction is magnetizing in nature due to a purely resistive load in the synchronous generator.

A. True
B. False

Question 6

Calculate the active power in a 2 ? resistor with 8 A current flowing through it.

A. 125 W
B. 128 W
C. 123 W
D. 126 W

Question 7

Calculate the active power in a 9.854 H inductor.

A. 4.98 W
B. 0 W
C. 8.59 W
D. 1 W

Question 8

Calculate the moment of inertia of the satellite having a mass of 79 kg and diameter of 83 cm.

A. 13.65 kgm2
B. 13.60 kgm2
C. 12.67 kgm2
D. 13.82 kgm2

Question 9

Calculate the phase angle of the sinusoidal waveform i(t)=sin(.6?t+?÷.88).

A. 100?÷88
B. 100?÷8
C. 100?÷8
D. ?÷88

Question 10

Calculate the reactive power in a 45 ? resistor with 1.78 A current flowing through it.

A. 28.8 VAR
B. 23.4 VAR
C. 25.82 VAR
D. 0 VAR

Question 11

Calculate the value of the frequency if the inductive reactance is 72 ? and the value of the inductor is 7 H.

A. 1.63 Hz
B. 1.54 Hz
C. 1.78 Hz
D. 1.32 Hz

Question 12

Calculate the velocity of the satellite if the angular speed is 87 rad/s and radius is 7.4 m.

A. 643.8 m/s
B. 642.4 m/s
C. 641.9 m/s
D. 643.2 m/s

Question 13

The slope of the V-I curve is 4.9°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.

A. .03 ?
B. .08 ?
C. .04 ?
D. .07 ?

Question 14

A particular current is made up of two components: a 10 A and a sine wave of peak value 14.14 A. The average value of current is _________

A. Zero
B. 24.14 A
C. 10:00 AM
D. 14.14 A

Question 15

A particular voltage is made up of two components: a 5 A and a cosine wave of peak value 7.8 A. The average value of voltage is _________

A. Zero
B. 35.14 A
C. 78 A
D. 5:00 AM

Question 16

Calculate the active power in a 2 Ω resistor with 8 A current flowing through it.

A. 125 W
B. 128 W
C. 123 W
D. 126 W

Question 17

Calculate the phase angle of the sinusoidal waveform i(t)=sin(.6πt+π÷.88).

A. 100π÷88
B. 100π÷8
C. 100π÷8
D. π÷88

Question 18

Calculate the reactive power in a 45 Ω resistor with 1.78 A current flowing through it.

A. 28.8 VAR
B. 23.4 VAR
C. 25.82 VAR
D. 0 VAR

Question 19

Calculate the value of the frequency if the inductive reactance is 72 Ω and the value of the inductor is 7 H.

A. 1.63 Hz
B. 1.54 Hz
C. 1.78 Hz
D. 1.32 Hz