Electrical Machine - I (3140913) MCQs

MCQs of DC Machines

Showing 41 to 50 out of 167 Questions
2 3 4 5 6 7
41.
Which of the following is/are the methods to reduce the armature reaction and its effects?
(a) pole chamfering
(b) pole stacking
(c) compensating winding
(d) all of the above
Answer:

Option (d)

42.
In DC machine torque depends on which of the following?
(a) flux (φ)
(b) armature current (I)
(c) both A and B
(d) speed
Answer:

Option (c)

43.
Compensating winding is placed in the
(a) pole shoe
(b) armature core
(c) main field
(d) all of the above
Answer:

Option (a)

44.
The direction of the current in the compensating winding is __________ to the direction of current in the armature conductors.
(a) same
(b) exactly opposite
(c) either of these
(d) none of the above
Answer:

Option (b)

45.
Which of the following is/are the advantages of carbon brush over the copper brush?
(a) They are not hard as copper brush
(b) They are self lubricating in nature
(c) In case of any sparking, they will be less damaged than copper brushes
(d) All of the above
Answer:

Option (d)

46.
The size of inter poles is small as compared to main poles. What is the reason?
(a) In order to not to get saturated
(b) In order to get saturated
(c) In order to get more flux
(d) All of the above
Answer:

Option (a)

47.
The functions of inter poles are
(a) nullify reactance voltage and improve the commutation
(b) reduce cross magnetization effect and improve commutation
(c) both 1 and 2
(d) none of the above
Answer:

Option (c)

48.
Which of the following statements is/are correct?
(a) Inter pole winding will act in the interpolar region
(b) Compensating winding will act under the pole
(c) Both A and B
(d) None of the above
Answer:

Option (c)

49.
In the DC machine shape of the main field, flux distribution is?
(a) triangular
(b) flat tapped or trapezoidal
(c) saddle shape
(d) peaky in nature
Answer:

Option (b)

50.
In the DC machine shape of the armature MMF wave is?
(a) Triangular and directed towards brush axis
(b) Triangular and directed towards the main pole
(c) Saddle shape
(d) Peaky in nature
Answer:

Option (a)

Showing 41 to 50 out of 167 Questions
2 3 4 5 6 7