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.