A technician connects a 12 V source across a composite lead made by firmly splicing together two solid cylindrical segments of equal diameter. The first segment is 3.0 m of copper, and the second segment is 2.0 m of aluminum. Both metals remain at the same ambient temperature so their intrinsic properties stay constant. The diameter of the composite wire is 2.00 mm throughout. Resistivities at the operating temperature are ρCu=1.68×10−8Ωm and ρAl=2.82×10−8Ωm. The internal resistance of the source is negligible.
(a) Compute the resistance of each metal segment individually.
(b) Determine the magnitude of the steady current that flows through the composite lead.
(c) Calculate the potential difference that appears across (i) the copper segment and (ii) the aluminum segment.
(d) For each segment, compute the rate at which electrical energy is converted to thermal energy. Identify which segment reaches the higher power dissipation and justify your answer quantitatively.