Halliday, Resnick & Walker — Maxwell's Equations; Magnetism of Matter: Problem 1

1 Uniform electric flux. Figure 32-19 shows a circular region of radius $R = 4.00 \text{ cm}$ in which a uniform electric flux is directed out of the plane of the page. The total electric flux through the region is given by $\Phi_E = (3.00 \text{ mV} \cdot \text{m/s})t$, where $t$ is in seconds. What is the magnitude of the magnetic field that is induced at radial distances (a) $2.00 \text{ cm}$ and (b) $5.00 \text{ cm}$? (c) At what radial distance is the field magnitude maximum?