2. The current density in a cylindrical wire of radius R = 2.0 mm is uniform across a cross section of the wire and is J = 2.0 x 10^5 A/m^2. (i) What is the current through the outer portion of the wire between radial distances R/2 and R. (ii) Suppose, instead, that the current density through across section varies with radial distance r as J = ar^2, in which a = 3.0 x 10^11 A/m^4 and r is in meters. What is the current through the inner portion of the wire (within r <= 1/2R)?