Suppose you have a cylindrical wire of radius a, where a parallel-plate capacitor is being charged. The gap caused by the capacitor between the wire is an imaginary cylinder with radius a and length d. Current I flows through the wire and charges +Q and Q accumulate on the parallel plates. In the past we have said that when charging a capacitor, the energy is stored in the electric field. Solve for the Poynting vector. And use the Poynting vector to solve for the rate at which the energy flows into the cylinder.

Suppose you have a cylindrical wire of radius a, where a parallel-plate capacitor is being charged. The gap caused by the capacitor between the wire is an imaginary cylinder with radius a and length d. Current I flows through the wire and charges +Q and Q accumulate on the parallel plates. In the past we have said that when charging a capacitor, the energy is stored in the electric field. Solve for the Poynting vector. And use the Poynting vector to solve for the rate at which the energy flows into the cylinder.