🔖 Topics

  • Definition of electric potential
  • Comparison of electric potential to electric potential energy
  • Relation of electric potential to electric field

🎯 Objectives

  • Calculate the electric potential some distance away from a point charge
  • Calculate the electric potential energy stored in a charge configuration from a given electric potential
  • Determine the orientation of electric field lines in relation to equipotential surfaces
  • Determine how the density of equipotential lines affects the strength of the electric field
  • Explain how electric potential lines are similar to a topographical map

📋 Sequence

  • We have studied electric field and force - field is just force per unit charge
  • We have studied electric potential energy - wouldn’t it be nice to have energy per unit charge?
    • Electric potential is energy per unit charge
  • Equipotential lines
    • Point charge
    • Parallel plates of charge
    • Electric dipole
  • Moving along versus across an equipotential line
  • Equipotential lines and electric field

🖥️ Animations, Simulations, Activities

📝 Practice Problems

A hydrogen atom has a single proton at its center and a single electron at a distance of approximately 0.0529 nm from the proton.

  1. What is the electric force that the proton exerts on the electron?
  2. What is the electric potential energy of the system?
  3. What is the electric field from the proton at the position of the electron?
  4. What is the electric potential from the proton at the position of the electron?

✅ Partial Solutions

  1. \(8.23 \times 10^{-8} \: N \) (attractive)
  2. \(4.36 \times 10^{-18} \: J \)
  3. \( 5.14 \times 10^{11} \: N/C \) (towards the proton)
  4. \( 27.22 \: V \)

📘 Connected Resources

  • Giambattista, Alan, et al. College Physics With an Integrated Approach to Forces and Kinematics. 5th ed., McGraw-Hill Education, 2020.
  • Mburu, Ted. E-Field Simulation. https://icphysweb.z13.web.core.windows.net/simulation.html. Accessed January 29, 2024.
  • Walsh, Tom. Equipotentials & Electric Field of Two Charges. https://ophysics.com/em9.html. Accessed January 29, 2024.