Consider an infinite plane of conductivity through which a constant current J=
flows. In this plane there sits a disk of radius 1 with conductivity . Normally this disk will distort the current flow as it is more conductive than the plane, however we will "cloak" this disk by placing an annulus 1 of less conductive material around the disk to counter act it's conductivity. Determine the necessary thickness of the annulus to successfully cloak the disk, that is find c.