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Homework Help: Voltage difference and potential energy help

  1. Mar 24, 2010 #1
    1. The problem statement, all variables and given/known data
    I'm really confused when it comes to distinguishing the potential difference and the voltage difference between the two oppositely charged plates. Could someone help clear things up? Like is the potential difference the work done in terms of the potential energy change when we move from the positive to the negative plate? For example, I read that the potential difference is the work done on a charge while the voltage difference is the work done per charge..what's the difference?


    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Mar 24, 2010 #2
    Re: Capacitance

    is your question what is the difference between voltage and the electric potential function (also notated as V in most texts)? Voltage and electric potential/scalar potential are two completely different things. Voltage is, what you said, the work per unit charge done by the electric field when a positive test charge is moved from point A to point B on a given path. Electric potential formula is: [Q / (4*pi*permittivity of free space constant*R)]. Let me know if this helps....
     
  4. Mar 24, 2010 #3
    Re: Capacitance

    yes i'm not sure what is the difference between the two because they seem like they're the same thing...which i know they're not..but like is there a specific difference between the two? do they both go against the electric field? do they both involve the potential energy?
     
  5. Mar 24, 2010 #4
    Re: Capacitance

    what do you mean by voltage "going against the electric field"? Voltage doesn't necessarily have to do anything with the E-field. Think about a circuit schematic. No E-field required.

    I suppose though, electrically speaking, potential and voltage are the same thing. However, potential and potential difference are NOT the same thing. Think about the temperature and the temperature difference, for example -> not equivalent. But if you're talking about the potential function, go back to my last post. Does this help?
     
  6. Mar 24, 2010 #5
    Re: Capacitance

    yes it does thanks!
     
  7. Mar 25, 2010 #6
    Re: Capacitance

    Not a problem!
     
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