The panel on the left displays an equipotential plot.  

What to do:  

1. Use the pencil to try your hand at sketching out electric field lines that are every where perpendicular to the equipotential lines shown.  
2. Start a new line by clicking the "draw off" button, and positioning the pencil  somewhere along the line you wish to draw.  (Hint: drag the pencil tip - watch for your mouse pointer to change shape.)  When you are ready to draw the field line, click "draw on", and drag the pencil tip to record the line.  When you have finished the line you are working on, click the "draw off" button.  Then reposition the dot, and start a new line.
3. Do your best - they don't have to be perfect! Once you have a few of them drawn, you should be able to use your drawing to identify the correct field plot.

Draw several electric field lines, and then pick the best Field Plot by clicking the links.

Which Field Plot most closely corresponds to the equipotential lines shown?
Field A
Field B
Field C
Field D

The region in the equipotential plot contains
two positive point charges.
two negative point charges.
one positive point charge, and one negative point charge.
None of the above.

The net charge in the region of the equipotential plot is
positive.
negative.
zero.