A copper wire of radius a = 0.214 mm has an aluminum jacket of outer radius b = 0.310 mm. There is a current i = 2.89 A in the composite wire. Take the resistivity for copper and aluminum to be 1.69 x 10-8?·m and 2.75 x 10-8?·m. Calculate the current (in A) in
(a) the copper and
(b) the aluminum.
(c) If a potential difference V = 9.00 V between the ends maintains the current, what is the length in meters of the composite wire?