1. Warm Up What is the SI unit for charge?
Calculate the electric force between two electrons that are 1.0 mm apart.

3. Electric Field Lines

4. Electric Field
A measure of the electric force a positive test charge would feel at any location
Test Charge – a unit charge used to measure the field
(There need to be two charges involved – one creating the electric field, Q, and the other that feels its effects, q.)

5. The farther apart the field lines, the weaker the force

6. Electric Field E = Fe / q Units: N/C
E represents the strength of the electric field
Q is the charge of the particle FEELING the field
Ex: A positive charge of 1x10-5 C experiences a force of 0.2 N when located at a certain point in an electric field created by a point charge of 3.4x10-3C. What is the electric field strength at that point?

7. Drawing electric field lines

8. Another try: Hint: which one is the field going away from?
Copy this view of one positive charge and one negative charge, and draw the electric field you think they’d create…
Hint: which one is the field going away from?
And toward which one?

9. Electric dipole field

10. Parallel plates that are oppositely charged
The electric field is the same at all points between parallel plates

11. What two things does an electric field tell us?
Magnitude
Direction