Product details

Planck's "quantum of action"  and extern photoelectric effect (line separation by a diffraction grating)

Planck's "quantum of action" and extern photoelectric effect (line separation by a diffraction grating)

Item no.: P2510502

print
  • Description
  • Scope of Supply
  • Downloads and Documents

Principle

The photoelectric effect is one key experiment in the development of modern physics. White light from a filament lamp is filtered by a grating spectrometer and illuminates a photocell. The maximum energy of the ejected electrons depends only on the frequency of the incident light, and is independent of its intensity. This law appears to be in contradiction with the electromagnetic wave theory of the light, but it becomes understandable in the frame of the corpuscular theory of light. The stopping voltage U0 at different light frequencies is determined by the I /U characteristicsof the photocell and plotted over the corresponding light frequency f .Plancks quantum of action is then determined from this graph.

Tasks

  1. Calculate the light frequency f  in dependence on the spectrometer angle
  2. Experimentally determine the stopping voltage U0 for different light frequencies and plot it over light frequency f
  3. Calculate Plancks constant from the dependence of the stopping voltage U0 on the light frequency f

What you can learn about

  • Photon energy
  • photon absorption
  • external photo effect
  • work function
  • photocell
  • quantum theory
  • Plancks constant
  • grating spectrometer

Follow us on
Facebook YouTube
PHYWE - excellence in science
  • 0
  •