Question

What is the value of Np in an average coil emf equation, for 10 armature conductors with 2 parallel paths?

(a) 2

(b) 3

(c) 2.5

(d) 4

The question was posed to me during a job interview.

I want to ask this question from EMF and Torque Production in section Circuit Model, Emf and Torque of DC Machines

Answer 1

Correct choice is (c) 2.5

The best I can explain: In an emf equation Nc= Cp * Np. Here, Cp= coils/ parallel path. Np is defined as number of turns per parallel paths which is also called as ratio of total armature conductors to the twice of number of parallel paths. Np= 10/(2*2)= 10/4= 2.5.