A copper wire and a zinc screw were attached to each 4 lemons. A copper wire attached to a lemon was connected to zinc screw in other lemon with a crocodile cable. Four lemon was connected to each other like this.The cable connected to a copper wire and the other cable connected to a zinc screw were left exposed.A LED lamp was connected to their ends.These processes were repeated for other fruits. Students understood that foods can produce electric current in small amounts and for a short time.
