Question

In a DC machine, the direct axis is __________

(a) Axes of main poles

(b) Axes perpendicular to axes of main poles

(c) Not determined from the poles position

(d) Can be drawn anywhere

I got this question in examination.

My question is based upon Armature Reaction -1 topic in portion Armature Reaction of DC Machines

Answer 1

Right choice is (a) Axes of main poles

To explain I would say: Direct axes is simply defined as the line passing through the axes of main poles. Maximum flux passes through this line. It’s also called as Direct Axis. Direct axes is always perpendicular to the geometrical neutral axis of machine.