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Electric Field Lines

  1. Oct 24, 2004 #1


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    Why are electric field lines always crossing equipotential lines at right angles? Can somebody please explain this to me? Thanks :smile:
  2. jcsd
  3. Oct 25, 2004 #2


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    Equipotential line or surface means that the potential is the same at every point. If two points are at the same potential then no work is done when a charge q is transferred from one point to the other. Take two points close to each other along the equipotential line, at a distance of ds, and decompose the electric field into components normal (En) and parallel (Es) to the line. The work done when the charge is transferred is simply q*Es*ds and this is zero, that is the electric field has only normal component to the equipotential line.

  4. Oct 25, 2004 #3


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    Didn't I answer this question already?? Please avoid duplicate posts of the same message.
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