The same fundamental mechanisms apply to all transformers. No-load losses are dominated by core hysteresis and eddy currents, present whenever the unit is energized. Load losses increase with current, driven by I²R in windings, eddy currents in conductors (skin and proximity effects), and stray flux heating metallic parts. Additional minor losses arise from dielectric heating, cooling system power consumption, and tap changer contact resistance. Design optimization aims to balance core and copper losses at expected operating load.