Here we have a thin cylinder made of copper with a cone made of graphite. When the surface integration/current density was measured at the apex, it came to -2.7 amps. When measured at the base, the current also read -2.7 amps. When the materials were switched around, the apex read -119 amps, while the base read -117.2 amps. This is due to copper being a much better conductor than graphite (which is composed of carbon).