University:
University of Cambridge
Course:
0625 IGCSE | Physics
Academic year:

2023
Views:

400

Pages:

2
Author:

Deddy A.

Electric Potential Electric potential energy: The change in the electric potential energy of a system consisting of a test charge, q, moving through a displacement, Ax, in a constant electric field, E, is given by the (negative) product of the charge, electric field and displacement. APE =-qV *PE is a scalar quantity Electric Potential V = Electric Potential Energy per unit test charge, volts ΔΡΕ (1 V = 1 J/C) AVVB-VA (1 V/m = 1 N/C) WO when Vo: VA (aka voltage) - electric potential diff. measure of the change in PE el per unit charge. Lo triggers flow of e V=PE/q Lo work done to move a unit of charge from one pt. to another Electric Potential for point charges. The electric potential, V, at a distance, r, caused by a single point charge, q, is V= ke Again the superposition principle holds: The electric potential due to multiple electric charges is the algebraic sum of the potentials due to each charge. This holds for each point in space. unlike e field superposition, which involves a sum of vectors, the superposition of e potentials reas. evaluating a sum of scalars. Potential energy of a pair of charges PE is (t) for 2 like charges. (+) work to bring them. together PE= 192 Peel of the pair of charges. Figure 16.7 (a) The electric poten- tial V at Pdue to the point charge gis Vkg (b) If a second charge, q, is brought from infinity to P, the potential energy of the pair PEk/ PROBLEM-SOLVING STRATEGY Electric Potential 1. Draw a diagram of all charges and circle the point of interest. 2. Calculate the distance from each charge to the point of interest, labeling it on the diagram. 3. For each charge q, calculate the scalar quantity V= The sign of each charge must be included in your calculations! 4. Sum all the numbers found in the previous step, obtaining the electric potential at the point of interest.