Voltage & Capacitors

Energy per charge, stored charge

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

• Voltage is electric potential energy per unit charge.
• Uniform field between plates: $E = V/d$.
• Capacitors store charge ($Q = CV$) and energy ($\tfrac12 CV^2$).

Steps

1. Uphill for charges
2. Voltage in a uniform field
3. Plate field
4. Capacitors
5. Before it sparks
6. Camera flash