The arrow representation for the electric field produced by more than
one source can become quite messy, even in two dimensions. Since
the field strength can change very rapidly and the length of an arrow is
proportional to the field strength, many arrows of different length must
be drawn, and the arrows start overlapping. (See here.) One
way around this is to only draw direction indicators (unit vectors).
You then loose the information about the field strength. Another way to graphically represent a
electric field is by
drawing **field lines**. If the rules for drawing field
lines are followed, then the direction of the field at any point is
given by the direction of a line tangent to the field line, while the
magnitude of the field is given qualitatively by the density of field
lines.

Click the buttons to choose different representations. You can also choose the sign of charges A and B.