Alternating Current

What “230 volts” means

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Mains is AC at 50 or 60 Hz.
• RMS voltage $= V_{\text{peak}} / \sqrt2$: 230 V RMS peaks at 325 V.
• RMS gives the same average power as an equal DC voltage.

Steps

1. A wave of voltage
2. Peak voltage
3. What a cup of tea costs
4. Sixty cycles
5. Using the RMS value
6. Why √2?