electrical

DC Motor MCQ Objective Questions and Answers Page - 1

1.

In the block diagram of a separately excited dc motor how does the armature induced emf appear as ?

Answer/ Hint      

Answer : B

Explanation :

2.

A 220 V dc machine has an armature resistane of 1Ω. If the full load current is 20 A , the difference of induced voltage, when the macine is running as a motor and generator is

Answer/ Hint      

Answer : C

Explanation :

3.

The current drawnby a 220 V dc motor of armature resistance 0.5Ω and back emf 200V is

Answer/ Hint      

Answer : A

Explanation :

4.

The current drawn by a 120 V dc motor with back emf of 110 V and armature resistance of 0.4Ω is

Answer/ Hint      

Answer : B

Explanation :

5.

In a dc motor energy conversion would not have been possible but for

Answer/ Hint      

Answer : B

Explanation :

6.

With the increase in speed of a dc motor

Answer/ Hint      

Answer : C

Explanation :

7.

If the back in a dc motor vanishes suddenly, the motor will

Answer/ Hint      

Answer : B

Explanation :

8.

The output power of any electrical motor is taken from the

Answer/ Hint      

Answer : C

Explanation :

9.

The armature shall must be able to withstand

Answer/ Hint      

Answer : D

Explanation :

10.

The output indicated on the name plate of any motor is always the

Answer/ Hint      

Answer : D

Explanation :

11.

A thicker wire is used in dc series motor  filed winding than that in a dc shunt motor.

Answer/ Hint      

Answer : D

Explanation :

12.

In case of a conductively compensated dc series motor , the compensating winding is provided

Answer/ Hint      

Answer : A

Explanation :

13.

The dc compounded motors are generally

Answer/ Hint      

Answer : B

Explanation :

14.

In a dc compounded motor the filed regulator is provided to

Answer/ Hint      

Answer : A

Explanation :

15.

The direction of rotation of a dc motor can be determined by

Answer/ Hint      

Answer : B

Explanation :

16.

The direction of rotation of a dc shunt motor can be reversed by interchanging

Answer/ Hint      

Answer : D

Explanation :

17.

When the supply terminals of a dc shunt motor are interchanged

Answer/ Hint      

Answer : B

Explanation :

18.

The direction of rotation of a dc series motor can be reversed

Answer/ Hint      

Answer : B

Explanation :

19.

The direction of rotation of a dc compound motor can be reversed by interchanging ___________connections 

Answer/ Hint      

Answer : A

Explanation :

20.

The speed of a dc motor is

Answer/ Hint      

Answer : B

Explanation :

21.

The speed of a dc shunt motor supplying a load at its rated speed can be reduced by

Answer/ Hint      

Answer : A

Explanation :

22.

A Dc shunt motor is operating at no load. If the armature is shunted by a resistance its speed will

Answer/ Hint      

Answer : C

Explanation :

23.

The shunted armature control method of speed control for dc shunt motors is

Answer/ Hint      

Answer : C

Explanation :

24.

The armature voltage control is considered suitable for a dc motor driven at constant

Answer/ Hint      

Answer : A

Explanation :

25.

For a constant supply voltage, what are the effects of inserting a series resistance in the filed circuit of a dc shunt motor, on its speed and torque ?

Answer/ Hint      

Answer : C

Explanation :

26.

In a Ward Leonard drive, if the filed current of the dc generator is suddenly reduced, the controlled dc motor operates

Answer/ Hint      

Answer : D

Explanation :

27.

Ward Leonard system for  controlling the speed of a dc motor is used where

Answer/ Hint      

Answer : D

Explanation :

28.

variation in speed by Ward Leonard control of dc motors occurs due to variation in

Answer/ Hint      

Answer : C

Explanation :

29.

No load speed of which of the following motor will be highest?

Answer/ Hint      

Answer : B

Explanation :

30.

No load speed of which of the following motor will be highest?

Answer/ Hint      

Answer : B

Explanation :

31.

The direction of rotation of a DC series motor can be changed by

Answer/ Hint      

Answer : B

Explanation :

32.

Which of the following application requires high starting torque?

Answer/ Hint      

Answer : C

Explanation :

33.

If a D.C motor is to be selected for traction motor would be

Answer/ Hint      

Answer : A

Explanation :

34.

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

Answer/ Hint      

Answer : B

Explanation :

35.

Which D.C motor will be preferred for constant speed line shafting?

Answer/ Hint      

Answer : C

Explanation :

36.

Differentially compound D.C motors can find applications requiring

Answer/ Hint      

Answer : B

Explanation :

37.

Which D.C motor is preferred for elevators?

Answer/ Hint      

Answer : D

Explanation :

38.

According to Fleming’s left-hand rule, when the forefinger points in the direction of the field or flux, the middle finger will point in the direction of

Answer/ Hint      

Answer : A

Explanation :

39.

If the field of D.C shunt motor gets depend while motor is running

Answer/ Hint      

Answer : C

Explanation :

40.

Starter are used wit D.C motors because

Answer/ Hint      

Answer : D

Explanation :

41.

In D.C shunt motors as load is reduced

Answer/ Hint      

Answer : C

Explanation :

42.

A D.C series motor is that which

Answer/ Hint      

Answer : A

Explanation :

43.

For staring a D.C motor a starter is required because

Answer/ Hint      

Answer : B

Explanation :

44.

The type of DC motor used for shears and punches is

Answer/ Hint      

Answer : D

Explanation :

45.

If a D.C motor is connected across the A.C supply it will

Answer/ Hint      

Answer : D

Explanation :

46.

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

Answer/ Hint      

Answer : A

Explanation :

47.

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

Answer/ Hint      

Answer : C

Explanation :

48.

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

Answer/ Hint      

Answer : A

Explanation :

49.

In a D.C shunt motor, speed is

Answer/ Hint      

Answer : A

Explanation :

DC Motor MCQ Objective Questions and Answers Page - 1
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