____________ losses are caused when a current flows in a conductor.

• A. Copper
• B. Iron
• C. No-load
• D. Load

Answer: (A)

This is about resistive heating in a conductor. When current flows, electrons collide with atoms, turning electrical energy into heat. The loss is proportional to the current squared times the conductor’s resistance, known as I^2R losses. Copper windings are used precisely because copper has low resistance, but any conductor with resistance will heat up under current. This type of loss is called copper losses. Iron losses, by contrast, come from the magnetic core (hysteresis and eddy currents) and aren’t caused simply by current flowing in a winding; no-load losses are overall losses present when the machine is energized but not delivering mechanical load.