fraid i have to agree with jwhite, sounds like you don't know how a transformer works. Mebbe some reading on that first at the local library would help.

Resistance varies with temperature, yes. Every material has a thermal co-efficient, changes it's dimensions as it heats, also changes the excitation energy available to the atoms hence changing the resistance, usually in a relatively linear way.

Magnetic field cause impedance, particularly if there is a variation in the field (changing current flow or core variation)based on lenz's laws of magnetics. This is derived from the inductance just as a resistive element has impedance derived from resistance.

Capacitors exhibit impedance properties also while i'm at it, charge on the plate will eventually reach saturation in a dc situation causing an open circuit and rising impedance based on capacitance.

Having said all that, i did work on a site wher half a dozen engineers took three days to work out why one of their number flew across a subyard after removing a 9VDC powered loop test unit from the secondary of an 3.3kV to 415 trannie.

Spock