Electric field lines
Electric field lines provide a means of viewing the electric field but are not quantitative. Since the electric field is a vector, electric field lines have arrows, showing the direction of the electric field. As an example,we show the electric field lines of a point charge and of a positive and negative charge.
The following rules apply to electric field lines:
Lines begin and end only at charges, beginning at + charges, disappearing at - charges.
Lines are closer together where the field is stronger.
Large charges have more field lines beginning/terminating at the charges.
Electric Field lines never cross.
For instance, the positive charge is stronger than the negative charge on the upper right diagram, since there are more lines originating from the positive charge and the lines from the negative charge are more strongly bent than the lines from the positive charge.