AP Physics Chapter 17
Electric Potential and Electric Energy;
Capacitance
17-1 Electric Potential and Potential
Difference
•Potential or electrical potential is the
potential per unit charge. Va=Pea/q
•Potential difference is the difference is the
work done by the electric force in moving a
charge from point a to b. Vab=Va-Vb=-Wba/q
•The SI unit for DV is the volt… J/C
DV=PEb-Pea=qVba
17-1 (Cont’d)
• See chart and diagram p 504
• See Example 17-1 p505
17-2 Relation Between Electric
Potential and Electric Field
• W=qVba
• W=Fd=qEd where d is the distance ll to
field lines from point a to b…
• qV=qEd …so V=Ed and E=V/d
• See Example 17-2 p 506
17-3 Equipotential Lines
• Equipotential lines, or in 3-D, equipotential
surfaces are areas of equal potential and
are perpendicular to the electric field at
any point. (See pg. 507 diagram.)
• There can be no electric field in a
conductor in the static state.
17-4 The Electron-Volt …a unit of
Energy
• 1eV= 1.6 x10-19J
• You must use the J value to calculate with
KE=1/2 mv2
17-5 Electric Potential Due to Point
Charges
• V=k Q/r = 1/(4pe0) (Q/r) for a single pt.
charge.
• See Example 17-3 p509
• See Diagrams pg 509
See Example 17-4 and 17-5 p510/511
HOMEWORK
• P522 1-8&10,13-14 due Tuesday BOP