Why does the experimental voltage of the secondary coil of a transformer differ from theoretical value?
In an ideal transformer, the voltage at the primary and secondary windings are always related exactly by the turns ratio, no matter what the current through the transformer may be. In a real transformer, there may be winding resistance and leakage reactance that can cause a voltage drop which is measurable at the terminals. You can find references to transformer equivalent circuit models that try to accurately estimate the performance of a real transformer. [1] and [2] are good references, but there are others out there. The winding resistance is just the wire resistance of each winding. The leakage reactance is an inductance that comes about from the fact that not all of the magnetic flux produced by the primary winding enters the secondary winding (and vice versa). So, the primary leakage reactance would be the self-inductance of the primary winding, since some flux produced by the primary loops back into the primary without entering the secondary. The secondary leakage reactance can
