Physics307L F09:People/Martin/Millikan Oil Drop

Millikan Oil Drop Summary

^{SJK 01:23, 19 November 2007 (CST)}

01:23, 19 November 2007 (CST)
Excellent work on this lab! You two took excellent data, and I like the analysis method you developed. Your Excel sheet looked good (and very austere with the black). I guess the summary could be more clear (take a look at Jesse's for example), but given your high quality work, I'm not going to nitpick now.  :) Furthermore, starting with Lab #4, I'm going to put far fewer comments on people's pages.

• Link to the lab manual: | Pasco for the Millikan Experiment.
• Link to my lab notebook for this experiment: [[1]]

Purpose

To experimentally determine electric charge and look for a quantization of this charge.

Results

Using this and excel to calculate the error in calculating slope I got:

• fundamental charge (e): [math]\displaystyle{ 1.52 \times {10}^-19 C }[/math]
• The uncertainty in this calculation: [math]\displaystyle{ 8.04 \times {10}^-21 C }[/math]
• Accepted value for e: [math]\displaystyle{ 1.6 \times {10}^-19 C }[/math]
• Relative error: 5%

How could I make this experiment better?

• To make the experiment more eye friendly I would like top have placed a camera on the microscope and looked at the display on a computer screen. This would have made looking and measuring the oil drops much easier.

Conclusion

• Overall I think our final result was great our error was 5%.

Possible sources of error

• We did observe some Brownian motion that could have affected our data.
• We had problems keeping track of the drops for extended periods of time, so our velocities were made up of at max a average of five measurements.
• The droplets would disappear and would come out not charged. This didn't effect the final result just made the experiment more annoying.
• overall I think that most of the error involved in our experiment was random error. We had no control over the charge on the oil droplets or the Brownian motion that we observed. There was some slight human error involved in the tracking of the oil droplets, it seems that Jesse and I were just terrible at it since we were the only ones to experience trouble tracking them.