Question:
Consider the situation of the previous problem. A charge of $-2.0^{\times 10^{-4}} \mathrm{C}$ is moved from the point $A$ to the point $B$. Find the change in electrical potential energy $\mathrm{U}_{\mathrm{B}}-\mathrm{U}_{\mathrm{A} \text { for }}$ the cases (a),(b)and (c).
Solution:
