Answer to Question #96792 in Electricity and Magnetism for k

Question

A charge of +0.25 C is moved from a position where the electric potential is 10V to a position where it is 90V what is the change in the potential energy of the charge ?

Answer 1

The change in potential energy of the charge is $q(\phi_2 - \phi_1)$, where $q = 0.25 C$ is charge, $\phi_2 = 90 V$ - final potential, $\phi_1 = 10 V$ - initial potential. The change is thus $0.25 C \cdot (90 V - 10 V) = 20 J$.