Explore how a Van de Graaff generator stores electric charge. Estimate sphere capacitance, voltage, electric field, and spark gap using safe educational physics formulas.
Best for students, teachers, science projects, classroom demonstrations, and quick electrostatic calculations.
Enter sphere radius, charge amount, and air condition to estimate voltage, capacitance, field strength, and spark distance.
A Van de Graaff generator is an electrostatic machine that moves electric charge onto a metal dome to create very high voltage at low current.
The dome acts like a spherical conductor that stores charge on its outer surface.
A belt transfers charge upward, where it is collected by the dome in a typical demonstration model.
As charge builds up, voltage rises and may produce visible sparks when the electric field breaks down air.
This educational calculator treats the dome as an isolated conducting sphere. A simplified sphere capacitance formula is used:
| Quantity | Formula | Meaning |
|---|---|---|
| Capacitance | C = 4πϵ₀R | Capacity of the dome to store charge |
| Voltage | V = Q ÷ C | Electric potential on the dome |
| Electric Field | E = V ÷ R | Approximate field near dome surface |
| Energy | U = ½CV² | Stored electrostatic energy |
Use the Van de Graaff generator tool in three simple steps.
Add the radius of the metal sphere or dome in centimeters.
Enter stored charge in microcoulombs and choose air condition for spark estimation.
Get estimated capacitance, voltage, electric field, spark gap, and stored energy.
Common questions about Van de Graaff generators and electrostatic calculations.