a. Current I is applied to point A of the medium, and current I is withdrawn from point B. Assuming that each point of the medium independently creates a stationary spherically symmetric current field, determine the surface current density in the plane of symmetry of points A and B. What is the total current through this plane? How will the solution change if a current I is applied to point B?
b. Determine the current density distribution over the ground surface if there is a point source with current I at a depth h from its surface.