DC Motors MCQ Multiple Choice Questions Answers - Page 2 | Quiz for Practice

Q: 16. The speed of a D.C. shunt motor more than its full-load speed can be obtained by

Correct Answer is: decreasing the field current

Q: 20. The type of D.C. motor used for shears and punches is

Correct Answer is: cumulative compound D.C. motor

Q: 21. These days D.C. motors are widely used in

Correct Answer is: electric traction

Q: 22. Three point starter can be used for

Correct Answer is: both shunt and compound motor

Q: 23. To get the speed of D.C, motor below the normal without wastage of electrical energy is used.

Correct Answer is: Ward Leonard control

Q: 24. Torque developed by a D.C. motor depends upon

Correct Answer is: all above factors

Q: 25. Usually wide and sensitive speed control is desired in case of

Correct Answer is: colliery winders

Q: 26. Ward-Leonard control is basically a

Correct Answer is: voltage control method

Q: 27. What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?

Correct Answer is: The armature may burn

Q: 29. When two D.C. series motors are connected in parallel, the resultant speed is

Correct Answer is: normal speed

DC Motors MCQ Questions for Practice

16. The speed of a D.C. shunt motor more than its full-load speed can be obtained by

decreasing the field current
increasing the field current
decreasing the armature current
increasing the armature current

17. The speed of a motor falls from 1100 r.p.m. at no-load to 1050 r.p.m. at rated load. The speed regulation of the motor is

2.36%
4.76%
6.77%
8.84%

18. The starting resistance of a D.C. motor is generally

low
around 500 Q
1000 Q
infinitely large

19. The total losses in a well designed D.C. generator of 10 kW will be nearly

100 W
500 W
1000 W
1500 W

20. The type of D.C. motor used for shears and punches is

shunt motor
series motor
differential compoutid D.C. motor
cumulative compound D.C. motor

21. These days D.C. motors are widely used in

pumping sets
air compressors
electric traction
machine shops

22. Three point starter can be used for

series motor only
shunt motor only
compound motor only
both shunt and compound motor

23. To get the speed of D.C, motor below the normal without wastage of electrical energy is used.

Ward Leonard control
rheostatic control
any of the above method
none of the above method

24. Torque developed by a D.C. motor depends upon

magnetic field
active length of the conductor
current flow through the conductors
all above factors

25. Usually wide and sensitive speed control is desired in case of

centrifugal pumps
elevators
steel rolling mills
colliery winders

26. Ward-Leonard control is basically a

voltage control method
field divertor method
field control method
armature resistance control method

27. What will happen if the back e.m.f. of a D.C. motor vanishes suddenly?

The motor will stop
The motor will continue to run
The armature may burn
The motor will run noisy

28. When the armature of a D.C. motor rotates, e.m.f. induced is

self-induced e.m.f.
mutually induced e.m.f.
back e.m.f.
none of the above

29. When two D.C. series motors are connected in parallel, the resultant speed is

more than the normal speed
loss than the normal speed
normal speed
zero

30. Where D.C. motor of H.P. 12 or more requires frequent starting, stopping, reversingand speed control

drum type controller is used
three point starter is used
four point starter is used
all above can be used