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Calculating Current given the number of electrons and positive ions

  1. Feb 16, 2009 #1
    1. The problem statement, all variables and given/known data

    In a fluorescent tube of diameter 3 cm, 10 *1018 electrons and 2.5 * 1018 positive ions (with a charge of +e) flow through a cross-sectional area each second. What is the current in the tube?

    2. Relevant equations
    Current is I = (delta Q)/(deta T)

    3. The attempt at a solution

    delta t is given as 1 second, but how do u calculate the change in charge given this information?
  2. jcsd
  3. Feb 16, 2009 #2


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    Homework Helper

    Use the charge on the electron. Note that the positive ions will go the opposite way to the electrons, so you must add the two currents.
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