1. Notes on Chapter 33 Electric Fields & Potential
Conceptual Physics
Notes on Chapter 33
Electric Fields & Potential

2. Electric Fields & Potential
“May the FORCE be with you”

3. Electric Fields & Potential
All particles have an electric field around them.
A electric field is a kind of aura that extends outward through space.

4. Electric Fields & Potential
To show the effects of the electric field, we use a “small test charge” (which is positive) to determine the direction and strength of the field.

5. Electric Fields & Potential
To show the effects of the electric field, we use a “small test charge” (which is positive) to determine the direction and strength of the field.

6. Electric Fields & Potential
Since the field has magnitude and direction it is
a vector and can
be represented
with vectors.
These vectors are called Field lines or Lines of force
(See fig pg. 519)

7. Electric Fields & Potential
Where these force lines are close together, the force is strong. Where the lines are farther apart, the force is weaker.

8. Electric Fields & Potential
Electric Shielding:
Because of mutual repulsion, electrons move as far apart as possible. On a hollow object, the interior will have NO CHARGE OR FIELD. The force on a test charge inside a hollow sphere will cancel to Zero

9. Electric Fields & Potential

10. Electric Fields & Potential
On odd shaped objects, the charge inside is still zero, but not uniform on the outside.

11. Electric Fields & Potential
Electric Potential Energy:
Remember chapter 8 when you lifted an object --- you did work on that object. The same thing applies here.
A test charge has
Potential Energy by
virtue of its position.

12. Electric Fields & Potential
If the test charge is “let go”, the potential energy will be transferred into kinetic energy of movement.

13. Electric Fields & Potential
Electric Potential = Electric potential energy
Charge
1 Volt = Joule_____
1 Coulomb
Note --- The voltage of a balloon rubbed on your head can be very high. But the electric potential energy is low because of the small amount of charge.

14. Electric Fields & Potential
Storage of Energy:
Electrical energy can be stored in a common device called a capacitor.

15. Electric Fields & Potential
A capacitor is a devise that has two plates separated by a small distance and connected to a battery.
Note --- this can be a Shocking experience if you are the discharging path !