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Electric Potential, Part 4

  • For a conductor, any excess charge must reside on the surface. Second, the electric field inside the conductor is zero. Third, E on the surface is perpendicular to the surface, and is given by sigma/epsilon_0, where sigma is the surface charge density. Fourth, the whole conductor is an equipotential region; i.e., all points on or within the conductor are at the same potential.
  • If a conducting sphere has a total charge Q distributed on its surface, the potential inside the sphere is given by kQ/R, where R is the radius of the sphere.
  • In a cavity within a conductor, the electric field is zero; if it were not, the inner surface of the conductor would not be an equipotential surface. The vanishing of E in the cavity explains why conductors are used as electrical shields.

Electric Potential, Part 4

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

AP Physics C: Electricity and Magnetism