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

Electric field at origin, zero or nonzero?

  1. Aug 18, 2011 #1
    1. The problem statement, all variables and given/known data

    Point charges +q and -q are placed at +50 cm and -50 cm on the x-axis, respectively. Is the electric field at the origin (halfway between the charges) zero or nonzero? If nonzero, which direction does it point?

    2. Relevant equations

    3. The attempt at a solution

    If they were like charges, both positive, then I would say the electric field would be 0. I'm not sure because they are opposite polarities. Please help.
  2. jcsd
  3. Aug 18, 2011 #2
    Try to think of the electric field lines; if you drew them what would they look like?
  4. Aug 18, 2011 #3
    What would happen if I were to place a charge of -q at the origin?
    How about +q? Would you agree that they would move? What does
    this say?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook