Maximum primary resistance: An ideal transformer is assumed to have zero resistance in its windings.
No flux leakage: This is the key feature of an ideal transformer; all the magnetic flux produced by the primary winding links with the secondary winding.
Hysteresis: While hysteresis losses can occur in real transformers due to the magnetic properties of the core material, an ideal transformer assumes no losses.
Eddy current: Similar to hysteresis, eddy currents are not present in an ideal transformer, which assumes a perfect core with no energy losses