1. A copper wire of length \(4 meters\) and cross-sectional area \(2\ mm^2\) has a resistance of \(0.03 \Omega\).
Calculate the resistivity of copper ______ \(\times\ 10^{-6}\)
2. The ratio of masses of two aluminium wires is \(4\ :\ 4\) and their corresponding ratio of lengths is \(1\ :\ 1\). Then, the ratio of their resistances is
The ratio of their resistance is :