1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What does 0 electric potential difference mean?

  1. Mar 28, 2014 #1
    This isn't a homework question, but while working on some questions in Physics AP C, i've come across several questions involving 0 PD (potential difference).
    My question is simple; what does 0 PD mean?
    so far i know that 0 potential difference of any kind is arbitrary, since it represents the amount of energy required to displace it from point a to b. Therefore i am aware that 0 does not really mean: 'no potential energy at that point'.

    Screen Shot 2014-03-28 at 11.09.25 PM.png
    (new to forum; i hope there's an image above this line^^)

    the image above is a simulation of 1 negative charge, and 3 positive charge with some distance between them. the white area supposedly shows 0 PD, but what is so special about it? Does a charge or an object behave differently in those areas?
  2. jcsd
  3. Mar 28, 2014 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    0 potential value is arbitrary; 0 potential difference is not.

    0 potential difference between two locations means that the potential values AT each point are the same.

    As to your specific question:
    What would be the effective force on a charged particle placed within the white region?
  4. Mar 28, 2014 #3


    User Avatar
    Gold Member

    As arildno stated, you're not being consistent with use of your termonology.
    [itex]U_{q}="Electric Potential"[/itex]
    [itex]V= "Potential Difference" = U_{q_{f}}-U_{q_{o}}[/itex]
    The second is what you measure with your ammeter in class.
  5. Mar 28, 2014 #4


    User Avatar
    Gold Member

    To actually answer your question, 0 electric potential is like setting a 0 for gravitational potential energy, put it where it's most convenient (probably ground in your circuit)
    0 Potential difference means that the 2 points your measuring between are at the same electric potential.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook