Lesson: Electric Fields of Point Charges Physics

Students will be able to

• relate the electric force, , on an object that has a charge of due to the presence of an electric field, , using the equation ,
• determine the electric field, , at a distance of from a point charge , applying the equation, , where is the Coulomb constant,
• recognize that an electric field can be represented by field lines,
• recognize that an electric field line must start at a positively charged object and terminate at a negatively charged object,
• recognize that an isolated positive charge has electric field lines starting from it that extend to infinity in all directions,
• recognize that an isolated negative charge has electric field lines terminating at it that extend from infinity in all directions,
• recognize that the directions of electric field lines in a region represent the directions of electric field vectors in the region,
• recognize that the density of electric field lines in a region represents the magnitude of the electric field in the region,
• recognize that the electric field lines of an isolated point charge are radial lines,
• rank and/or estimate the electric charge values of point charges by inspecting the diagrams of the field lines of the resultant electric fields around the point charges.