1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

Invisible charge?

  1. Jun 15, 2013 #1


    User Avatar
    Gold Member

    "Invisible" charge?

    HI all,

    1. The problem statement, all variables and given/known data
    See attached picture. q1 is at equal distance from A or B.
    k = coulomb's constant

    2. Relevant equations

    VA = (k q1 / r)
    VB = (k q1 / r)

    3. The attempt at a solution

    VAB = VA - VB = 0 V

    It seems that the charge becomes invisible in that case, right?

    Attached Files:

  2. jcsd
  3. Jun 15, 2013 #2


    User Avatar
    2017 Award

    Staff: Mentor

    The charge is not invisible.

    We have (roughly) the same gravitational potential everywhere on the surface of earth. Is earth invisible? Do you float freely in space?
  4. Jun 16, 2013 #3


    User Avatar
    Gold Member

    That's right but its effect on voltage difference is the same as if there was no charge.
  5. Jun 16, 2013 #4
    Any charge configuration admits equipotential surfaces. The potential difference between any two points on such a surface is zero. Which does not mean there is no charge.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Threads - Invisible charge Date
Charged pendulum in magnetic field Saturday at 12:36 PM
Net electric force on a charge Thursday at 11:53 PM
Using Optics To Make An Aircraft Invisible Oct 27, 2011
Invisibility of flint glass rod in carbon disulfide Jun 7, 2006
Invisible's Homework House Dec 4, 2004