Introduction
Question 1:
Question 2:
Question 3:
In all the points from the air-gap we have:
We make the transition from the intensity of the field in the air-gap to the induction in the air-gap with the help of relation
being perpendicular on the air-gap surface, the flux through each of the air-gap portions, for , will be:
because the angular opening of the areas in wich the armature are opposite is between for and for
intensity of the field in the air-gap to the 
induction in the air-gap with the help of 
relation 
flux through each of the air-gap portions, for 
, will be:
,
for 
and 
for 