This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Schaltbild Franck Hertz Versuch. Prinzipschaltbild des FranckHertz Versuches own assumed Journey gemalt von Tom Sawyer Vacuum tube circuits Experiment of Franck and Hertz
Page 2023 Free-images.com. All images are Public Domain