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Oil drop experiment ?

  1. Jul 1, 2010 #1
    when Robert Millikan did the oil drop experiment to measure the charge of an electron .
    they balanced the gravitational force of the oil drop with the electric field .
    did they use F=qE , did they know how many electrons were in their oil drops .
  2. jcsd
  3. Jul 1, 2010 #2


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    Yes, that and F=mg.

    No, they only knew that it was an integer multiple and they examined the charge on many individual drops to try and determine what number they were a common multiple of.
  4. Jul 2, 2010 #3
    ok thanks for your answer .
  5. Jul 2, 2010 #4


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    In retrospect, it turned out Millikan also used a bit of http://www1.umn.edu/ships/ethics/millikan.htm" [Broken].

    It might've been one of the biggest frauds in science - if he hadn't been correct. Food for thought.
    Last edited by a moderator: May 4, 2017
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