As the load on the transformer is increased, the core losses:

Losses in the transformer:

1.) Core loss:

• It is a loss that happens in the core of a transformer when it is subjected to the change in magnetic flux \((\phi = {V \over f})\)
• Hence, core loss depends upon supply voltage and frequency.
• Core losses remain constant with an increase or decrease in the load.
• Core loss is the sum of eddy current loss and the hysteresis loss.
• The induced emf produces a current known as eddy current. The losses due to this current are known as eddy current losses.
• The losses in a transformer that are due to magnetization saturation in the core are known as hysteresis losses.

2.) Copper loss:

•  The losses produced due to heat produced by electrical currents in the transformer windings are known as the copper losses.
• These losses increase with an increase in loading conditions.

3.) Stray magnetic losses:

• The losses occurring in the transformer due to the presence of external magnetic field nearby transformer are known as stray magnetic losses.