# DC Motors MCQs Quiz Multiple Choice Questions & Answers

## Test Your Skills in DC Motors Quiz Online

Dive into the world of DC Motors with our comprehensive collection of multiple-choice questions and answers. Whether you're a student studying electrical engineering, a technician working with motors, or simply intrigued by the principles of electromechanical systems, our meticulously curated selection covers a wide range of topics. Explore fundamental concepts such as motor types, operating principles, speed control methods, and practical applications in various industries. With our user-friendly interface and detailed explanations, mastering the intricacies of DC motors has never been more engaging and accessible. Start your journey towards understanding this essential component of electrical machinery today!

## DC Motors Questions with Answers

1. The condition for maximum power in case of D.C. motor is

2. The current drawn by the armature of D.C. motor is directly proportional to

3. The direction of rotation of a D.C. series motor can be changed by

4. The hysteresis loss in a D.C. machine least depends on

5. The losses occurring in a D.C. generator are given below. Which loss is likely to have highest proportion at rated load of the generator ?

6. The main disadvantage of the Ward-Leonard control method is

7. The mechanical power developed by a shunt motor will be maximum when the ratio of back e.m.f. to applied voltage is

8. The plugging gives the

9. The power mentioned on the name plate of an electric motor indicates

10. The purpose of retardation test on D.C. shunt machines is to find out

11. The ratio of starting torque to full-load torque is least in case of

12. The speed of a D.C. motor can be varied by varying

13. The speed of a D.C. series motor is

14. The speed of a D.C. shunt motor can be increased by

15. The speed of a D.C. shunt motor is required to be more than full load speed. This is possible by

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

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

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

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

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

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

22. Three point starter can be used for

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

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

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

26. Ward-Leonard control is basically a

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

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

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

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

32. Which D.C. motor has got maximum self relieving property ?

33. Which D.C. motor is generally preferred for cranes and hoists ?

34. Which D.C. motor is preferred for elevators ?

35. Which D.C. motor will be preferred for machine tools ?

36. Which D.C. motor will be suitable alongwith flywheel for intermittent light and heavy loads?

37. Which method of braking is generally used in elevators ?

38. Which motor has the poorest speed control?

39. Which motor should not be started on no-load ?

40. Which of the following application requires high starting torque ?

41. Which of the following law/rule can he used to determine the direction of rotation of D.C. motor ?

42. Which of the following load normally needs starting torque more than the rated torque?

43. Which of the following loss in a D.C. generator is dissipated in the form of heat?

44. Which of the following loss in a D.C. generator varies significantly with the load current ?

45. Which of the following losses are significantly reduced by laminating the core of aD.C. generator ?

46. Which of the following method of speed control of D.C. machine will offer minimum efficiency ?

47. Which of the following motor has the poorest speed regulation ?

48. Which of the following motor is preferred for operation in highly explosive atmosphere ?

49. Which of the following motors is most suitable for signalling devices and many kinds of timers ?

50. Which of the following motors is usually used in house-hold refrigerators ?