Question

If in the DC machine, the reversal of current in the coil is faster than ideal or linear commutation then the commutation is said to be __________ commutation.

(a) Retarded

(b) Curvilinear

(c) Accelerated

(d) Under

The question was posed to me in a national level competition.

I want to ask this question from Commutation Process in section Commutation Process & Excitation Methods of DC Machines

Answer 1

Right choice is (c) Accelerated

The explanation is: Speed of the commutation is dependable on change in an induced current direction. When reversal of current in coil is faster then, obviously change of coils are taking place at faster rate. Thus, commutation is said to be accelerated commutation.