Copper losses of a transformer are also called ______.

• A. Core losses
• B. Load losses
• C. No-load losses
• D. Flux losses

Answer: (B)

Copper losses are the resistive losses that occur in the windings when current flows, so they grow with load. In transformer loss classification, losses are split into no-load (core) losses and load losses. The load-loss group includes the winding copper losses plus stray winding losses, and copper losses are the main part of it. That’s why copper losses are called load losses. Flux losses isn’t a standard term, and no-load losses refer to core losses, which are separate from the winding resistive losses.