Principle
A photocell is illuminated with monochromatic light of different
wavelengths from a filament lamp with interference filters. The
maximum energy of the ejected electrons in the photo-cell
depends only on the frequency of the incident light, and is
independent of its intensity. The stopping voltage Uo at
different light frequencies is determined by the U/I caracteristics
of the photocell and plotted over the corresponding light frequency
f. Planck's quantum of action or Planck's constant (h) is
determined from this graph .
Tasks
To determine Planck's quantum of action from the photoelectric
voltages measured at different wave lengths
What you can learn about
- External photoelectric effect
- Work function
- Absorption
- Photon energy
- Anode
- Cathode