Home Topics Quiz Login

Commutation - DC Machines MCQs

Commutation MCQs : This section focuses on the "Commutation" in DC Machines. These Multiple Choice Questions (MCQs) should be practiced to improve the DC Machines skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.

Question 1

___________ the change that takes place in a winding element during the period of a short circuit by a brush.

A. Excitation
B. Commutation
C. Generator
D. Motors

View Answer

Question 2

How many methods to obtain Sparkless commutation?

A. 1
B. 2
C. 3
D. 4

View Answer

Question 3

The time required to change the current through a coil from Ic to -Ic is called?

A. Commutation Period
B. Commutation Time
C. Commutation Set
D. Commutation Count

View Answer

Question 4

Commutation is delayed due to __________

A. Leakage reactance
B. Effect of armature reaction
C. Because of other factors
D. Leakage reactance and armature reaction

View Answer

Question 5

For a DC machine, in a commutator ________

A. Copper is harder than mica
B. Mica and copper are equally hard
C. Mica is harder than copper
D. Cannot be determined

View Answer

Question 6

The insulating material used between the commutator segments is normally _______

A. Graphite
B. Mica
C. Paper
D. Air gap

View Answer

Question 7

If Time taken > Tc, then known as?

A. under commutation
B. delayed commutation
C. Both A and B
D. accelerated commutation

View Answer

Question 8

Which are the methods for getting an ideal commutation?

A. Resistance commutation
B. Voltage commutation
C. Current commutation
D. Both A and B

View Answer

Question 9

If Time taken < Tc , then over or accelerated commutation.

C. Can be true or false
D. Can not say

View Answer

Question 10

If the current reversal is completed by the end of commutation period, it is called ideal commutation.

A. Yes
B. No
C. Can be yes or no
D. Can not say

View Answer