Question

The resistance of a wire of length 100cm diameter 0.3mm is found to be 3.0 ohms Calculate (1) the resistivity (2) the conductivity of the material of a wire

Answer 1

$\rho=\frac{\pi Rd^2}{4l}=2.12\cdot 10^{-7}~Ohm\cdot m,$

$\sigma=\frac 1\rho=4.7~MSm.$