Lab 3
Photoelectric Effect
Bill Chun Wai Hung
Friday Section
30 April 2004
Calculation:
From the graph, the slope is 4 x 10-15, which is =4 x 10-15 where e=10-19C
h = 4 x 10-34
Percentage difference = = 39.6%
Conclusion by Bill Chun Wai Hung:
1. Principles and Results
Einstein took E=hf, and later a
correcting function called the work function W was added to the resulting
equation.
By rearranging the equation, the equation becomes
If the equation is divided by e=10-19C, the equation becomes
By plotting a graph of V versus f, the slope is . The experimental value of is 4 x 10-15, and the experimental value of h is 4x10-15. The percentage difference is 39.6%.
2. Error Analysis
The error of the experiment may be
caused by the limited significant figure of the equipments, like the frequency
was recorded to the 3 sig. fig. Besides, when the slope is generated in the
plotting, the significant figure dropped to 1 significant figure, the lack of
significant figure in the calculation gives a larger percentage difference, so
the result looks farther from the target value.
When the data points of V are recorded,
the reading was kind of fluctuating, which gives small errors to the final h
value.