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Concepts

Conduction in gases

Overview

Two long metal rods are connected to a step-up transformer. When the power is turned on, a voltage is created between the two rods that exceeds the dielectric breakdown of air. As a result, a spark forms across the rods where they are nearest to each other. As the heated ionized air rises, the spark appears to move upward until the trail of ionization breaks since it becomes less stable as it grows longer.

Details

Equipment

• [1] Step-up transformer connected to metal rods
• [1] Clear plastic tube

Safety Equipment

• [2] Safety glove

Important Notes

• Lethal voltage is used in this experiment. Wear safety gloves when handling the apparatus.
• Please unplug the transformer after you are finished.

Script

1. Put on your safety gloves.
2. Place the plastic tube to cover the exposed metal rods.
3. Connect the transformer to a power source.
4. Turn on the transformer.
5. When finished, turn off the transformer.

Additional Resources