A copper wire has a circular cross section with a radius of 2.46 mm. HINT (a) If the wire carries a current of 3.93 A, find the drift speed (in m/s) of electrons in the wire. (Take the density of mobile charge carriers in copper to be n = 1.10 x 1029 electrons/m3.) 1.09e-5 X m/s (b) For the same wire size and current, find the drift speed (in m/s) of electrons if the wire is made of aluminum with n = 2.11 x 102 electrons/m3. m/s