# Magnetic permeability and optical impedance

Homework Statement:
Determine the value of optical impedance
Relevant Equations:
Z = μ . c/n
Hi,
It's given that an electromagnetic wave (5.10^14 Hz) travelling in an environment with the index n = 1,33, where the magnetic permeability (μ) is equal to the magnetic permeability in a vacuum (μ0).
The optical impedance (Z) is given by the formula : Z = μ . c/n.
I tried to turn μ into μ0 to determine its value but I didn't manage to get any further than determining the value of the relative electrical permittivity (εr) = 1,769.
Sorry if I have misused any vocabulary because I'm translating this from french.
Thank you so much for your help!

Steve4Physics
Homework Helper
Gold Member
I tried to turn μ into μ0 to determine its value but I didn't manage to get any further than determining the
That doesn't make sense, but it might be a language problem.

What is the magnetic permeability of a vacuum (μ0)? Look up this standard value if you don't already know it.

the magnetic permeability (μ) is equal to the magnetic permeability in a vacuum (μ0).
So, you now know how big the magnetic permeability (μ) is.

Since you know μ, c and n you can now work out Z using your formula. I don't see the problem.