The watt is the SI unit of power — 1 joule per second. Named after James Watt. Common examples: LED bulb 5–10 W, laptop 45–100 W, kettle 2000–3000 W, car engine 50,000+ W.
Real-world: LED bulb: 5–10 W. Laptop: 45 W. Kettle: 2200 W. Oven: 2000 W. Sun per m² on Earth: 1361 W/m².
Read full watt reference →The volt-ampere equals one watt for purely resistive loads, but differs from watts for inductive or capacitive AC loads. Used for transformer, UPS and generator sizing — which must handle apparent power, not just real power.
Real-world: Home UPS: 600–1500 VA. Transformer: kVA ratings. Motor power factor typically 0.8 — 1 kW motor = 1.25 kVA.
Read full volt-ampere reference →