Yuri,
I think you would better understand what is happening
if you view the inductance in question as half of
a transformer, where the other half is the aether.
This allows you to bring in the formular NxI one side =
NxI the otherside. This way you can see that I is constant.
If it wasn't a constant then the lines of flux would have a
very distorted shape at one end of the inductance.
The fact that transformers have impedances that are not
totally resistive is because of other factors than Inductance.
If I am incorrect with this analogy I would apreciate any
corrections as I am sure Yuri would to
Art