I1, I2 - currents through the primary and secondary winding

V1, V2 - voltages

N1, N2 - number of turns

F1, F2 - magnetic fluxes through core, produced by the currents I1 and I2 (they are opposing...)

R - the reluctance of the core

We have V1/V2 = N1/N2 = I2/I1.

F1=N1*I1/R; F2=N2*I2/R

I think I1 and I2 are in phase too.

That means F1 and F2 are practically equal.

How can we have a nonzero resulting flux through the core? F=F1-F2

If the flux through the iron core is zero,

**then the cause that produces V2 (variation of the flux) does not exist**, then V2=0?

I know I'm wrong, but i don't know where is the mistake...