1.  Click on each contour plot in turn and print it out.

2.  On the equipotential plot of the parallel plate configuration, make a sketch of at least 5 electric field lines by following the procedure below.

• Starting at the mid-potential equipotential line, pick a starting point anywhere.

• Sketch a line from the equipotential there to the next equipotential in such a way that it comes in perpendicular to that equipotential.

• Continue by constructing a perpendicular line to the next equipotential.

• Repeat this process in both directions until the electrodes are reached.

Do the same thing for 4 more starting points on the mid-potential equipotential line.

3.  Repeat the same procedure for the point electrodes configuration.

4.  Estimate the electric field strength at the midpotential point in both equipotential plots by using the definition:

Take the difference between two adjacent equipotentials and divide by the distance between them to get the field strength at that location. Record the value as a number directly on the equipotential plots at the appropriate location.