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

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

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

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

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

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

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

33.7 The Van de Graff Generator Van de Graff Generator- high voltages are built up on a surface –Charges are distributed evenly on surface –Very large charge is possible (MV range!) MythBusters: Van de Graff Generator –