Chapter 21, Problem 68P

Figure 21.37 shows a rectangular box with sides 2a and length L surrounding a line carrying uniform line charge density A. The line passes directly through the center of the box faces. Integrate the field of the line charge over strips of width dx as shown to find the electric flux through one face of the box. Multiply by 4 to get the total flux, and show that your result is consistent with Gauss’s law.

FIGURE 21.37 Problem 68