Core losses in transformers are comprised of hysteresis and eddy currents.

• A. False
• B. Partly true
• C. True
• D. Not defined

Answer: (C)

Core losses in transformers consist of two mechanisms: hysteresis losses and eddy current losses. Hysteresis losses come from the magnetic domains in the core material not aligning instantly with the changing magnetic field as the AC waveform cycles, so energy is dissipated as heat with each cycle. Eddy current losses arise because the changing magnetic flux induces circulating currents in the conductive core, and these currents also heat the material. The total core loss is the sum of these two components, while copper losses come from the resistance of the windings and are separate from core losses. Therefore, the statement is true.