Electric field lines

Electric
field lines

Electric field lines
provide a means to visualize the electric field.
Since the electric field is a vector, electric
field lines have arrows showing the direction of the electric
field. As two examples, we show the electric field lines of a single
point charge, and of a positive and negative charge.

The following rules
apply to electric field lines:

1. Lines begin
   and end only at charges (beginning at + charges,
   ending at – charges) or at Infinity.

2. Lines are
   closer together where the field is stronger.

3. Larger charges
   have more field lines beginning or ending on them.

4. Electric
   Field lines never cross (since E must point in a definite
   direction unless it is zero).

5. At any location, the
   direction of the electric field is tangent to the electric field
   line that passes through that location.

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.

Examples     Electric fields
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