Van de Graaff Candle

A candle placed near the dome of a Van de Graaff generator responds to the electric field by deflecting its flame.

- Set up the Van de Graaff generator with a discharge rod nearby.

1. Place a lit candle in a holder so that the flame is level with the dome and about 6 inches away.
2. Turn on the generator and observe how the candle flame deflects toward or away from the dome.
3. For a stronger effect, position the candle between the dome and the discharge rod and watch the flame dance as ions move in response to the electric field.
4. When finished, turn off the generator and safely discharge the dome with the grounding rod.

Physics demo: Fire plus Van De Graaff - Rhett Allain:

📄 Van de Graaff - Candle - IOWA Department of Physics & Astronomy: https://instructional-resources.physics.uiowa.edu/5b3040-van-de-graaff-candle

• Try varying the distance between the candle and the dome to see how flame deflection changes.
• Compare the behavior of a small tea-light flame versus a tall taper candle.
• Use incense sticks instead of a candle to create visible smoke trails that show the movement of ionized air.

• Keep all flammable materials, clothing, and hair away from the candle flame.
• Always use a stable candle holder to prevent tipping.
• Use the grounding rod to safely discharge the Van de Graaff after the demo.
• Perform in a well-ventilated area but away from strong drafts that may interfere with the flame.
• Do not leave an open flame unattended.

• Why does the candle flame lean toward or away from the dome?
• What role do charged particles (ions) play in this effect?
• How does the electric field of the Van de Graaff extend into the space around it?
• What similarities does this have with natural lightning or other atmospheric electrical phenomena?
• Would the effect be the same in a vacuum or without ionized gases?