Two cylindrical conductors with equal cross sections but different resistivities are put end-to-end. Find the magnitude of the charge that accumulates at the boundary between the conductors if a current \(I=100\textrm{A}\) flows in the wires. The wires are made of aluminum and copper with resistivities \(\rho_{Cu}=1.7 \times 10^{-8} \Omega\cdot m\) and \(\rho_{Al}=2.8\times 10^{-8} \Omega \cdot m\), respectively. This charge should be very small even for this large current \(I=100A\).
by
David Mattingly
