Question

1) What are the rules for drawing and using electric field lines

2) What does a vector in an electric field line diagram mean/represent?

Answer 1

1)

The rules for drawing electric field lines for any static configuration of charges are

1. The lines begin on positive charges and terminate on negative charges.

2. The number of lines drawn emerging from or terminating on a charge is proportional to the magnitude of the charge.

3. No two field-lines ever cross in a charge-free region. (Because the tangent to the field line represents the direction of the resultant force, only one line can be at every point.)

4. The line approaches the conducting surface perpendicularly.