7. Equipotential Lines and Electric Fields

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Learning Objectives

  • To be able to describe the meaning of equipotential surfaces and how they relate to electric field lines.


Course Notes

Read through the course notes before watching the video.  The  course note files may also contain links to associated animations or interactive simulations.

Read sections 3.5 through 3.9:
Electric Potential (PDF)


Lecture Video

Video Excerpts

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Learning Activities

Guided Activities

Read through the class slides. They explain all of the concepts from the module.

Slides (PDF)


Do the Concept Questions first to make sure you understand the main concepts from this module. Then, when you are ready, try the Challenge Problems.

Concept Questions

Concept Questions (PDF)

Solutions (PDF)

Challenge Problems

Challenge Problems (PDF)

Solutions (PDF)

Problem Solving Help

Watch the Problem Solving Help video for insights on how to approach and solve problems related to the concepts in this module.

Problem 1: Two Metal Spheres Far Apart at the same Potential

A metal sphere has radius 0.24 meters and charge 3.5x10-8 Coulomb. What are the electric field and potential at the surface of the sphere, if we assume the potential is zero at infinity. Now the first sphere is connected by a long thin conducting wire to an initially uncharged sphere and with radius 0.062 meters many meters away. After electrostatic equilibrium is reached, what is the charge on each sphere, and what are the electric fields and potentials at the surface of each sphere. Assume that there is no charge on the wire.

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