Is the electrostatic force between a point charge and a neutral metallic object always attractive?
Author(s)Levin, Michael; Johnson, Steven G.
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We give an example of a geometry in which the electrostatic force between a point charge and a neutral metallic object is repulsive. The example consists of a point charge centered above a thin metallic hemisphere, positioned concave up. We show that this geometry has a repulsive regime using both a simple analytical argument and an exact calculation for an analogous two-dimensional geometry. Analogues of this geometry-induced repulsion appear in many other contexts, including Casimir systems.
DepartmentMassachusetts Institute of Technology. Department of Mathematics
American Journal of Physics
American Association of Physics Teachers (AAPT)
Levin, Michael, and Steven G. Johnson. “Is the Electrostatic Force Between a Point Charge and a Neutral Metallic Object Always Attractive?” American Journal of Physics 79.8 (2011): 843. Web. 26 June 2012. © 2011 American Association of Physics Teachers
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