Question

In a DC machine, z, p, Ia and a are respectively the number of conductors, number of poles, armature current and number of parallel paths. The peak value of fundamental component of armature MMF wave is ____________

(a) 8/Π[(z/2p)(Ia/a)]

(b) 8/Π^2[(z/p)(Ia/a)]

(c) 4/Π[(z/2p)(Ia/a)]

(d) 8/Π^2[(z/p)(Ia/a)]

The question was posed to me in an internship interview.

Question is from MMF Produced by Distributed Windings in section Synchronous Machines of Electrical Machines

Answer 1

The correct option is (d) 8/Π^2[(z/p)(Ia/a)]

For explanation I would say: The peak value of the fundamental sine component Fa for a DC machine is Fa=8/Π^2[(z/p)(Ia/a)] AT/pole.