The potato radio

• The copper wire and the carbon rod must not touch each other in the potato.

• The copper wire can be obtained from a locksmith (metalworking companies) or electrician and the carbon rod from a specialist store for drawing and painting materials.

Cut off the plug of the headphones and remove a small piece of insulation from the two cables. Now insert the copper wire and the carbon rod into the raw potato at a distance of about 2 cm. Then hold one of the two cables of the headphones to the carbon rod and the other to the copper wire.

• 1 raw potato
• 1 copper wire
• 1 carbon rod (alternatively a zinc wire)
• 1 headphone

• The copper wire and the carbon rod must not touch each other in the potato.

• The copper wire can be obtained from a locksmith (metalworking companies) or electrician and the carbon rod from a specialist store for drawing and painting materials.

What is technically behind the experiment

This simple experiment shows how electrical energy is generated in the potato. The potato represents the battery in the circuit. (See also explanations on the apple battery). The experiment also works with an apple, a lemon or vinegar instead of the potato. With a lemon or an apple, the acid is easy to recognize as an important component for the electrochemical process. It is amazing that the experiment also works with a potato. But the potato also contains acids.

Stefanie Hellmold & Rebekka Bartsch