PHOTO-ELECTRIC EFFECT 'PLANCK'S' DIGITAL METERS, LAMP & FILTERS
New version of the Photo Electric Effect with 2 separate meters. One displays the current through the Photo Tube in 0.1 nanoamps and the other displays the backing volts that brings the current to exactly zero. With both readings on view without the need for switching, experiments are faster and less confusing.
The light source is by the traditional method of a white light source and colour filters.