The question is about Cm term.
We have coupled inductors.
The voltage across first coil is
And I am ok with it. I understand it.
I know that current I1 causes a flux in the magnetic core
Where c is
But I cannot understand the first formula. How do we get Cm term?
I thought there would must be
My misunderstanding does not relate to the nature of Cm or C1 terms. I do not understand how do we get it mathematically.