the copper track on a printed circuit board is made from copper foil 35um thick. the width of the track is 0.16cm and the resistivity of copper is 1.69x10^-8ohms. what is the resistance of 1cm of track?
A sample of Si has electron and hole mobilities of 0.13 and 0.05 m /V-s 2 respectively at
300 K. It is doped with P and Al with doping densities of 21 3 1.510 / m and
21 3 2.510 / m respectively. The conductivity of the doped Si sample at 300 K is