Problem 1
The figure shows a thin plastic rod of length L and uniform positive charge Q lying on an x axis. (a) With V=0 at infinity, find the electric potential at point P1 on the axis, at distance d from the rod. (b) Next, substitute variable x for d and find an expression for the magnitude of the component Ex of the electric field at P1. (c) Find the direction of Ex relative to the positive direction of the x axis. (d) From the symmetry, determine Ey at P1. (e) Now, consider that the rod has a nonuniform linear charge density ̀=cx. With V=0 at infinity, find the electric potential at point P2 on the y axis at y=D. (f) Find the electric field component Ey at P2. (g) Why cannot the field component Ex at P2 be found using the result of (e)?