What is the difference between ideal transformer and practical transformer?

Answer 1

There are basically 4 major differences :-

1. The windings (both primary and secondary) of an ideal transformer are

considered to have zero resistance, hence the transformer is lossless.

2. There is no leakage flux in an ideal transformer.

3. The permiability of the core material in ideal transformer is considered to be

tending to infinity and hence the current needed to set up the flux in the

transformer is negligible.

4. There is zero hysterisis and eddy current losses in an ideal transformer.

Answer 2

An ideal transformer is the one whose windings do not have any ohmic resistance and whose core does not have any leakage flux and eddy current losses.
A practical transformer is the one whose windings do have some amount of ohmic resistance and the core also have some leakage flux and eddy current losses.