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Homework Help: A couple of electric potential theory problems

  1. Feb 16, 2005 #1
    A couple of electric potential "theory" problems

    OK, so let's say Person A is on Planet A, where the ground potential is 1,000,000 V. Person A touches an object insulated from ground at a potential of 1,000,001 V. Person B is on Planet B, where the ground potential is 0 V. Person B touches an object insulated from ground at a potential of 200 V. Who, if anyone, experiences a shock?

    My answer is that Person A gets a huge shock and dies and Person B gets a pretty significant shock because the objects are both insulated from ground. Not really sure at all though.

    The second question is: Work is required to push a solitary electron into an electric field where it attains an electric potential of 1 volt. If you instead psuh 2 electrons through the same path, the electric potential of the two electrons will be:

    I would assume that the electric potential of the two electrons would be 2 volts. Is this stupid?

    And finally: The same question as above. But instead the question is, what is the work required to move the electrons?

    I figure if the electric potential achieved by one electron is one volt, but you instead push two electrons, it would be 2 electronvolts.

    (I should mention this is multiple choice, the answer possibilities are: 1 eV, 2 eV, 4 eV, 1/2 eV, 1/4 eV).

    If these answers are wrong, can someone try to point me in the rightish direction?
  2. jcsd
  3. Feb 16, 2005 #2
    Ok think about tit this wya you get a shock because of the potential DIFFERENCE

    For person A since he's on the ground his potential is also 1,000,000V right?
    Since he touches the object (at 1,000,000V) how much current has to flow from the object to the ground through the person?Since V = iR and here v =1 volt, i = 1/R

    Now for the second part use the similar concept how much cureent has to flow from the object to trhe ground through the person? Since V = 200, i = 200/R

    Through which person has more current flowed? Who will experience a bigger flow of electrons (a shock) through himself?

    Think about the second part this way-

    To move an electron from zer oto 1 volt is like moving an electron from the positive plate to the middle of a parallel plate system. When you moved two electrons how much will each gain? So your answer is right

    And Since W = qV how much work to move a charge of 1q to a potential of 1V?
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