In this activity, students explore the concept of equipotentials around point charges. Students use the simulation to plot equipotentials and observe the patterns near a single positive charge, near two positive charges, and near a positive and a negative charge. Students also explore the relationships between the electric fields associated with these charges and the equipotentials they plot.
Before the Activity
Students should be familiar with the concept of electric fields and the electic field patterns near simple arrangements of point charges prior to this activity. Students should also be introduced to the concept of electric potential and the formula for calculating electric potentials near point charges prior to this activity. Teachers may find it helpful to relate the concept of equipotentials to the concept of contours on a topographical map.
During the Activity
Students will plot several equipotentials around each arrangement of charges. Data points are recorded by holding the Ctrl button and pressing the decimal point button. When plotting the equipotentials, the points should be close enough together to form a relatively smooth curve, but far enough apart that the curve can be completed in a reasonable amount of time. If a data point needs to be removed, the x and y coordinates of the point can be deleted from the Lists and Spreadsheet page. Students should ignore the line which connects one equipotential to another.