DC Series Motors Speed MCQs : This section focuses on the "DC Series Motors Speed". These Multiple Choice Questions (MCQs) should be practiced to improve the DC Series Motors Speed skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
780 V, 97 A, 1360 rpm separately excited dc motor with armature resistance (Ra) equal to 9 ohms. Calculate back emf developed in the motor when it operates on one-fourth of the full load. (Assume rotational losses are neglected)
A. 564.75 V
B. 561.75 V
C. 562.45 V
D. 565.12 V
Question 2
Calculate the moment of inertia of the hollow cylinder having a mass of 78 kg and radius of 49 cm.
A. 9.363 kgm2
B. 9.265 kgm2
C. 9.787 kgm2
D. 9.568 kgm2
Question 3
Calculate the power developed by a motor using the given data: Eb= 48 V and I= 86 A (Assume rotational losses are neglected.)
A. 4128 W
B. 4150 W
C. 4140 W
D. 4170 W
Question 4
Calculate the radius of the circular ring having a moment of inertia 59 kgm2 and mass of 69 kg.
A. .924 m
B. .928 m
C. .934 m
D. .944 m
Question 5
Calculate the value of the angular acceleration of the motor using the given data: J = 81 kg-m2, load torque = 74 N-m, motor torque = 89 N-m.
A. .195 rad/s2
B. .182 rad/s2
C. .183 rad/s2
D. .185 rad/s2
Question 6
Calculate the value of the frequency if the time period of the signal is 99 sec.
A. 0.08 Hz
B. 0.02 Hz
C. 0.01 Hz
D. 0.04 Hz
Question 7
The generated e.m.f from 45-pole armature having 400 turns driven at 70 rev/sec having flux per pole as 90 mWb, with 17 parallel paths is ___________
A. 13341.17 V
B. 12370.14 V
C. 14700.89 V
D. 15690.54 V
Question 8
The slope of the V-I curve is 31°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.
A. 0.600 ?
B. 0.607 ?
C. 0.543 ?
D. 0.648 ?
Question 9
The unit of Magnetic flux density is Tesla.
A. True
B. False
Question 10
Turn-on and turn-off times of transistor depend on _________
A. Static Characteristic
B. Junction Capacitance
C. Current Gain
D. Voltage Gain
Question 11
The slope of the V-I curve is 31°. Calculate the value of resistance. Assume the relationship between voltage and current is a straight line.
A. 0.600 Ω
B. 0.607 Ω
C. 0.543 Ω
D. 0.648 Ω