Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Millikan Oil Drop Issue

  1. Aug 6, 2012 #1
    I completed the Millikan oil drop lab in class with as much accuracy as possible. I used the PASCO interface and used a very accurate Air pressure calibration. My final experimental charge of the electron derived from the equation in the lab was, 1.8 x 10 ^-19 C. When I turned in my lab, I was docked points for having a "very rare" one electron on the oil drop analyzed even though the percent discrepancy is something like 12.5 percent compared to the theoretical charge of the electron. Would I be wrong to contest this?

    edit- usually the charge contained on one drop is due to several electrons and dividing by the theoretical charge gives you how many electrons are on it. I got one electron on the drop and got docked
     
    Last edited: Aug 6, 2012
  2. jcsd
  3. Aug 6, 2012 #2
    how much cahrge did you get on a drop...if it was only 1.8 x 10-19C then it looks strange because that is close to exactly 1 electron
     
  4. Aug 6, 2012 #3
    That is the exact computed number from the equation
     
  5. Aug 6, 2012 #4
    wow..that is strange, sounds like you had a drop with exactly one electron on it.
    Not impossible but also not likely.
    Did you have lots of measurements on drops to get a final answer?
     
  6. Aug 6, 2012 #5
    Took 6 times up and 6 times down averages them separately and computed from there
     
  7. Aug 7, 2012 #6

    mfb

    User Avatar
    2016 Award

    Staff: Mentor

    If I remember correctly, in this experiment I had 2 drops with a single electron, too. 2 out of ~30, with most somewhere in the range of 2-10 electrons.

    You cannot measure the elementary charge with a single drop only. How many electrons did you have in the other drops?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Millikan Oil Drop Issue
  1. Millikan's oil drop (Replies: 0)

Loading...