The depth of penetration of a wave in a lossy dielectric increases with increasing

The intrinsic impedance of copper at high frequencies is

The polarization of a wave with electric field vector $$\overrightarrow E = {E_0}\,{e^{j\left( {\omega t - \beta z} \right)}}\left( {\overrightarrow {{a_x}} + \overrightarrow {{a_y}} } \right)$$ is

Copper behaves as a