1. Chapter 33: Electric Fields and Potential Conceptual Physics Bloom High School

2. 33.1 Electric Fields • Electric Fields- similar to a gravitational field • Acts at a distance • Can be positive OR negative • Test Charge- used to determine the strength of a field and/or the direction of the field • Always positive • “Direction” can be positive or negative

3. 33.2 Electric Field Lines • Electric field is a vector quantity • Magnitude and direction • Arrows extend from positive charges and toward negative charges • Lines closer together represent a stronger field • Physics Physlets I.23.2, I.23.3, P.23.2 (PhET Charges & Fields 2.04)

4. 33.3 Electric Shielding • Shielding- charges spread evenly over the surface • Charges don’t extend into the object

5. 33.4 Electric Potential Energy • PE- energy based on location • Gravitational PE- location between objects & mass • Electrical PE- location between objects & charge • Physics Physlets I.25.2

6. 33.5 Electric Potential • Electric potential (V) • Electric potential energy ÷ charge • Volt (Allesandro Volta) • 1 Volt = 1Joule/Coulomb • A Coulomb is a large amount of charge, so everyday objects can have large amounts of voltage, but would have small charges • A balloon can have thousands of Volts but only a millionth of a Coulomb

7. 33.6 Electric Energy Storage • Capacitor- stores electrical charge • Used in all circuitry • Storage based on voltage, size of plates and gap between plates • Physics Physlets I.26.1

8. 33.7 The Van de Graff Generator • Van de Graff Generator- high voltages are built up on a surface • Charges are distributed evenlyon surface • Very large charge is possible (MV range!) • MythBusters: Van de Graff Generator • http://www.youtube.com/watch?v=7qgM1A3pgkQ