To connect two devices, you need a \(40 \mathrm{~m}\) long copper wire. If the needed resistance of the wire is \(0.5 \Omega\), then what should be the diameter of the wire? If the voltage drop across the wire is \(10.0-\mathrm{V}\), then what is the current flow to each device? \(\left[ho_{\text {copper }}=1.68 \times 10^{-8} \Omega \cdot \mathrm{m}\right]\)