1. A copper wire of length \(2 meters\) and cross-sectional area \(1\ mm^2\) has a resistance of \(0.04 \Omega\).
Calculate the resistivity of copper ______ \(\times\ 10^{-6}\)
2. The ratio of masses of two aluminium wires is \(1\ :\ 4\) and their corresponding ratio of lengths is \(2\ :\ 1\). Then, the ratio of their resistances is
The ratio of their resistance is :