Physics307L F08:People/Franco/Franco's Planks Constant

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SJK 15:17, 17 December 2008 (EST)
15:17, 17 December 2008 (EST)
Ignoring problems with the 2nd order, etc., good statistical analysis in this lab. Missing here is a comparison of your discrepancy of your final value from the accepted value relative to your uncertainty. That is: your result is inconsistent and systematic error is indicated.

Planks Constant

For this experiment, we tested photon theory of light, and found that the classical theory did not apply at the quantum level. We also observed the effects of particle and matter interaction; were a photon would strike a piece a metal. If that incoming photon has enough kinetic energy to overcome the work function and replace the electron, then it would produce a voltage. If the frequency of that photon is high, so is the energy by this relation E=hf. As for planks constant the experimental value is (4.55 +/- .16) x 10^-15 eV*s, and as for the accepted value 4.135669212e-15 ± 1.2407e-21 eV*s. Here the results from the lab for planks constant and the work function:

  • Experimental value for h: (4.55 +/- .16) x 10^-15 eV*s
  • Experimental value for Wo: 1.642 +/- .092 eV
  • Current accepted value of Planks Constant: 4.135669212e-15 ± 1.2407e-21 eV*s
  • Accepted Value of the Work Function: (1.36 +/- .08) eV
  • Percent Difference in h: 10.05 %
  • Percent Difference in Wo: 17.22 %

As for the time charge, we used that section of the experiment to support the photon theory of light with different colors of light. We noticed that higher frequency gave us higher voltage without having to increase the intensity of the lamp, not that it would matter. We also noticed that there was a max voltage due. We even noticed an equipment glitch, were some of the voltage was leaking out in the system. We also notice that if you filter the photons it takes longer time to reach that max voltage. Thus proving the photon theory of light.