We used an ideal transformer in the previous equations (without any energy losses). However, some energy losses do occur in actual transformer for the following reasons:
Flux Leakage: Because some flux leaks from the core, not all flux generated by the primary coil make it to the secondary coil. This occurs as a result of the core's inadequate design or the presence of air holes in the core. It is possible to lower it by wrapping the primary and secondary coils over each other. It can also be lowered if the core is well-designed.
Windings Resistance: Because the wire used for the windings has some electrical resistance, energy is wasted as a result of the heat generated in the windings. These are mitigated in high current, low voltage windings by utilizing thick wire with a high conductive substance.
Eddy Currents: The alternating magnetic flux creates eddy currents in the iron core, resulting in energy losses through heating. By using a laminated core, the impact is decreased.
Hysteresis Loss: In each AC cycle, the alternating magnetic field reverses the magnetization of the core. The loss of energy in the core occurs as heat owing to hysteresis loss, which is minimized by employing a magnetic material with a low hysteresis loss.