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Homework Help: Physics deriving planck's constant

  1. Nov 9, 2013 #1

    im trying to do this homework, where i have to derive plancks constant using an experiment where we used some LED lights of different wavelengths to work out voltage at different wavelengths. From that i worked out the frequency and ekmax of the electrons given out. however i have no idea how to derive plancks constant from this and my teacher was rushing everything so no one understood anything, i dont know the reason behind why we did the experiemnt in that way.

    why did LED lights light up and isnt the photoelectric effect the release of electrons? so why were we seeing whther the LED was lighting up or not at different resistaances?

    please help thanks
  2. jcsd
  3. Nov 9, 2013 #2
    Is there some way you might be able to provide us with a scan of the relevant sections of your lab manual?
  4. Nov 10, 2013 #3
    this is as level, there is no lab manual
  5. Nov 10, 2013 #4
    we need to plot a graph and the gradient of that graph will be plancks constant
  6. Nov 10, 2013 #5
    Energy can be measured in electron volts (eV) where e is the electron charge, if that helps.
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