Measuring the resistance of a block.

The resistance in a conductor is proportional to the length of the conductor and inversely proportional to its cross section. If we apply a voltage V to the $1\times2$ face, the current will be given by $I_{xy}= \frac{V}{\rho} \frac{x y}{z}$ where $x=1 cm, y=2 cm, z=3 cm$ and $\rho$ is the resistivity of the material. By comparing the ratios $\frac{xy}{z}$ , $\frac{xz}{y}$ and $\frac{yz}{x}$ we find that $\frac{I_{max}}{I_{min}}= 9 \rightarrow I_{max}=9 \textrm{mA}.$