Physics307L:People/Gibson/Notebook/070910: Difference between revisions
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==Setting Up== | ==Setting Up== | ||
To begin this lab | |||
==Experiment 1 - The Photon Theory of Light== | ==Experiment 1 - The Photon Theory of Light== |
Revision as of 10:37, 17 September 2007
Setting Up
To begin this lab
Experiment 1 - The Photon Theory of Light
NOTE: DVM reads incorrectly for producing a 0 potential through the h/e apparatus. It reads at a (+) .04V
All measurements are using the first order spectral lines with the Variable transmission filter.
Ultra-violet maxima stopping voltage readings - (NON TRANSMISSION LENS - 2.15)
2.09V in 3.06 seconds at 100%
2.09V in 4.89 seconds at 80%
2.09V in 5.49 seconds at 60%
2.09V in 6.99 seconds at 40%
2.09V in 9.69 seconds at 20%
Violet maxima stopping voltage readings - (NO TRANSMISSION LENS - 1.78)
Previously we calculated these values: 1.73V in 5.91 seconds at 100%
1.73V in 3.83 seconds at 80%
1.73V in 3.53 seconds at 60%
1.73V in 4.18 seconds at 40%
1.73V in 8.70 seconds at 20%
They turned out to be somewhat incorrect NEW VALUES:
1.74V in 3.63 seconds at 100%
1.74V in 5.37 seconds at 80%
1.74V in 5.58 seconds at 60%
1.74V in 7.71 seconds at 40%
1.74V in 14.90 seconds at 20%
Blue maxima readings - (NO TRANSMISSION LENS - 1.57V)
1.53V 4.71 seconds - new trial 1.97 100%
1.53V 3.70 seconds - new trial 3.13 80%
1.54V 2.70 seconds - new trial 4.03 60%
1.54V 3.50 seconds - new trial 5.76 40%
1.54V 6.69 seconds - new trial 6.60 20%
Green maxima stopping voltage readings - (NO TRANSMISSION LENS .91V W/O GREEN FILTER 1.05V)
.91V 6.91 seconds at 100%
.90V 8.15 seconds at 80%
.90V 10.90 seconds at 60%
.90V 16.99 seconds at 40%
.90V 26.77 seconds at 20%
Yellow maxima stopping voltage readings - (NO TRANSMISSION LENS .77V W/0 YELLOW FILTER 1.11V)
.76V 5.62 seconds at 100%
.76V 6.17 seconds at 80%
.76V 8.73 seconds at 60%
.76V 15.03 seconds at 40%
.76V 30.65 seconds at 20%
In our search for determining how to figure out the frequency order of the color spectrum we (Matt G and I) found a wiki website: Color spectrum and for EM spectrum where we obtained most of our formulas and the actual value of Planck's constant.
- [math]\displaystyle{ \lambda = \frac{c}{f} \,\! }[/math]
and
- [math]\displaystyle{ E=hf \,\! }[/math]
or
- [math]\displaystyle{ E=\frac{hc}{\lambda} \,\! }[/math]