Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Electric Potential and Capacitance

  1. Apr 19, 2006 #1
    I know that Electrostatic Potential at a point due to a point charge is defined as the amount of work done in bringing a unit positive charge to that point (working against the electric force)

    But, I am unable to reconcile this definition with the phrases like "Potential of a conductor"

    More specifically, I read that "The potential of a conductor increases as we deposit more charges on it"

    First of all, what is meant by potential of a conductor? Potential due to what?

    Secondly, why should the potential increase linearly with the charge?

    If someone could answer, I would appreciate it
  2. jcsd
  3. Apr 19, 2006 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    What you described earlier is not the electrostatic potential, but rather the electronstatic potential energy. That's why you can equate it to work done. This has units of energy.

    The electrostatic potential has units of "volts" or equivalent. This also has a dimension of energy/unit charge. However, because "potential" and "potential energy" are really measured either as a CHANGE or with respect to a reference value, one can sometime use the term "potential difference".

    Now I'm saying that because you included a "capacitance" in the title even though you said nothing about a capacitor in your post. So I will assume that what you mean by adding charge to a conductor means you add charge to one plate of a capacitor. What this can do is to increase the potential difference between the two sides of a capacitor. The "V" or potential difference in volts is now different. Or you can say the amount of work done per unit charge in moving a charge from one plate to the other is equivalent to V. You can also say the amount of work done in moving a charge q from one plate to the other is qV, etc... etc.

    You may also want to read this thread:


Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Electric Potential and Capacitance
  1. Electric Potential (Replies: 2)