Question

What is the total ampere turns/pole (in AT/pole) if 600 lap wound conductors carry 120A current through conductors (P=4)?

(a) 18000

(b) 9000

(c) 4500

(d) 13500

The question was posed to me in an online interview.

My doubt stems from Armature Reaction in chapter Armature Reaction of DC Machines

Answer 1

The correct option is (b) 9000

To explain: Ampere-conductors/pole =ZIc/P= Zla/AP. Ampere turns per pole is calculated by multiplying total no. of conductors with the current carried by them divided by the twice the total no. of poles.

Ampere-turns/pole = 600*120/8 =18000/2= 9000 .