Copper losses these losses occur in the windings of

Copper losses
These losses occur in the windings of the transformer when heat is dissipated due to the current passing through the
windings and the internal resistance offered by the windings. So these are also known as ohmic losses or I2R losses,
where ‘I’ is the current passing through the windings and R is the internal resistance of the windings.
These losses are present both in the primary and secondary windings of the transformer and depend upon the load
attached across the secondary windings since the current varies with the variation in the load, so these are variable
losses.
Mathematically, these copper losses can be defined as:
P
ohmic
= I
p
R
p
+ I
s
R
s
Iron losses
These losses occur in the core of the transformer and are generated due to the variations in the flux. These losses
depend upon the magnetic properties of the materials which are present in the core, so they are also known as iron
losses, as the core of the Transformer is made up of iron. And since they do not change like the load, so these losses
are also constant.