Monthly Archives: February 2018

Explore the Electric Dipole Field

The purpose of the dipole field simulation is to let the user explore the electric and potential fields surrounding one or two electric charges.  A complete worksheet is available to guide students in this exploration.  Note the following: 

  • The number of E-lines is proportional to the charge in Coulombs (C).   
  • The E-field strength is proportional to the density of the E-lines
  • Equipotential (Voltage) rings surround each charge. 
  • The gradient in voltage is proportional to the E-field.  

In order access the electric dipole simulation website, use the following information:

Student Worksheet Downloadable Word Doc

We used the following word document as a lab procedure in the PHY112 class.  However, it can be used possibly in PHY101 as well, because questions are qualitative.


Points for Discussion
  • The electric field is a force field: The force on a positive charge has direction parallel to the electric field lines. The magnitude of force is proportional to the density of the E-field lines.
  • All electric field lines start on a positive charge and terminate on a negative charge.
  • If the positive charge is bigger than the negative charge, or if the negative charge is zero, some E-lines appear to go out to infinity. This is true in principle, but in real life, the lines do terminate on some distant negative charge. There do not appear to be any concentrations of positive or negative charge at any location in the universe — the charges are matched with each other over fairly short distances.