The electric field in three different wires (I,II,III) made of the same metal, with current flowing in the wires, is shown below. (The rest of the circuit, including the battery, is not shown.) The electric field in each wire is:E1=E3=0.050,0,0V/m andE2=0.800,0,0V/m. WiresIandIIIhave a diameterd1=0.005m, and WireIIhas a diameterd=1.2510-3m. In WireI,6.191018electrons flow per second at an average drift speed3.510-6m/s.

E3 E1 E d - - - -- d1 dz D C A B x=1.6 m x=0.6 m *=0 x=0.5 m