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Homework Help: Calculating potential difference

  1. Oct 26, 2008 #1
    I have done 1, i cant get the right answer for question 2. i seem to be getting minus7.5 volts. i know thats not anywhere near right because you can't get a minus voltage. i have tried many different ways to do this and i still cant get the right answer

    To get question 1 i used ohms law which gave me the two answers shown in the attachment, for question 2 i tried using the same method, but that gave me the wrong answer so i tried finding the conductance and from the resistance and the current, but that gave me - 7.5 volts. i ma very confused an i think i might be missing something very simple

    View attachment 16093
    Last edited: Oct 27, 2008
  2. jcsd
  3. Oct 28, 2008 #2


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    Homework Helper

    Hi sallyishyper,

    Your attachment does not seem to be there.
  4. May 3, 2010 #3
    I couldn't get the attachment either, says that there is an error.
  5. May 3, 2010 #4


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    Science Advisor
    Homework Helper

    Hi sallyishyper! :smile:

    Can you give us the url of your picture? :wink:
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