1. Not finding help here? Sign up for a free 30min 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!

Dipole in an external electric field

  1. Jan 10, 2015 #1
    1. The problem statement, all variables and given/known data
    Why isn't the expression for torque on a dipole kept in an external electric field ExP? Why is it PxE?
    No such indication has been given in any of the derivations, that it is mandatory for it to be PxE, so why can't it be ExP?

    2. The attempt at a solution
    Is it all about experiments?
     
  2. jcsd
  3. Jan 10, 2015 #2

    gneill

    User Avatar

    Staff: Mentor

    What's the essential difference in the cross products A x B versus B x A?
     
  4. Jan 10, 2015 #3
    The direction of the resultant of A x B is just opposite to that of B x A...
     
  5. Jan 10, 2015 #4

    gneill

    User Avatar

    Staff: Mentor

    Right. So it comes down to the definitions of positive or negative directions for quantities in the chosen coordinate system. This includes assumed directions for positive or negative torques, angular velocities, etc., which are vector quantities (or pseudo vector quantities in some cases, but that's another topic).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Dipole in an external electric field
Loading...