Contact potential difference

[Imagin_e]

Homework Statement

Hi!
I'm writing my lab report on the Franck-Hertz experiment and I have trouble with the contact potential difference (inelastic collision). How do you calculate it?

Homework Equations

See below

The Attempt at a Solution

The energy differences between the maximum and minimum peaks lies around 4.9 eV (4.9 +/- 0.5 eV approx.) , which is the "correct" value. When it comes to the contact potential difference, I guess that I can calculate it by calculating the average between two peaks and then subtract it from the first peak? But I'm not sure.

 

[Asim Riaz]

The contact potential difference (CPD) is the difference in energy between two distinct energy levels. It can be calculated by subtracting the energy of the lower level from the energy of the higher level. In the case of the Franck-Hertz experiment, the CPD is the difference between the maximum and minimum peaks. This can be calculated by subtracting the energy of the minimum peak from the energy of the maximum peak.