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Homework Help: 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 24, 2004 #2


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    Since the potential cannot vary along an equipotential surface its gradient can only have a component perpendicular to the surface. The electric field is proportional to the gradient of electrical potential. Therefore, the electric field must be normal to an equipotential surface.
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