1. The problem statement, all variables and given/known data I know that for air, the intrinsic impedance η is 377 Ω, but it becomes complex in a conductive medium. This fact is sort of hindering me in being able to answer a few problems consisting of electric and magnetic waves in a conductive medium, but I just wanted to clarify one thing. Say, I am given H(z,t)=0.5cos(ωt-βz)ay+0.7cos(ωt-βz)ax 2. Relevant equations I know that the intrinsic impedance for a conductive medium is: 3. The attempt at a solution When σ=0 for one problem, I was left with: But I do know that My question is, what in the world is u_o, ε_o, and ε_r ??? Am I supposed to figure this out or is this already provided in a table somewhere? I have been trying to look in my book and online, but am getting confused easily. Will someone please clarify this for me? Any help is greatly appreciated!