D.C. motor control

What happend when there are three north poles&one south pole
in four pole d.c.machine,instead of two north poles&two south poles. explain.

 

[SteveKW]

You now have a SIX pole machine. NORTH, south, NORTH, south, NORTH & SOUTH. The all CAPS being your physical poles and the two other south poles being "consequent" (induced or ghost) poles. This will slow the motor down and make it run very badly and have a lot of electrical noise as it runs and probably burns up.