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Electric potential problem

  1. Jan 11, 2016 #1
    1. The problem statement, all variables and given/known data
    https://fbcdn-sphotos-h-a.akamaihd.net/hphotos-ak-xfp1/v/t1.0-9/12417589_10205411987170709_6390638921146727371_n.jpg?oh=e166de7d1246b4afacebe60bac5ce654&oe=570B03E4&__gda__=1460454017_6cad38b2934b81eeeccbeedf05704e4b

    2. Relevant equations
    Electric potential
    3. The attempt at a solution
    Is electric potential a vector quantity?
    So that mean both charges product electric potential and result in zero at P?
    How should i start for question 17a?
     
  2. jcsd
  3. Jan 11, 2016 #2

    cnh1995

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    Homework Helper

    No. It is scalar.
     
  4. Jan 11, 2016 #3

    QuantumQuest

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    Gold Member

    Electric potential is a scalar. Now, what does it mean that potential at P is zero? You have two isolated point charges, that each one produces an electric field around it. So, how can the potential at P be zero? Answering that, you can immediately see that using this fact and a simple formula, you can calculate point charge at B.
     
  5. Jan 11, 2016 #4
    That mean kq/r+kq/r=0 something like that?
     
  6. Jan 11, 2016 #5

    QuantumQuest

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    What would be the potential at point P, if you didn't have point charge at B? But you have this point charge at B and potential at P is zero. So, you have a zero from two scalars (V). What does this imply for the second potential (i.e. regarding B)?
     
    Last edited: Jan 11, 2016
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