Each battery has an emf of 1.6 volts. each wire is 24 cm long, and has a diameter of 0.0007 meters. the wires are made of a metal which has 7e+28 mobile electrons per cubic meter; the electron mobility is 4e-05 (m/s)/(v/m). a steady current runs through the circuit. the locations marked by "x" and labeled by a letter are in the interior of the wire.