What is the value of εr in a lossless dielectric with μr = 1?

[formulajoe]

H = 30 sin ( 2*pi*10^8*t - 5*x) in the z direction milli-amp/meter.
First question is if μr = 1, find εr.

H is the magnetic part of a plane wave in a lossless dielectric.
I don't see any way to find εr from the information that's been given.

 

[StatusX]

What is the speed of the wave? How does the speed relate to the dielectric constant?

 

[formulajoe]

just had a thought, if the square root of μr*εr = 5, than μr = 25 correct?

 

[StatusX]

I think you mean εr, and if μr is 1, then that is obviously true.

 

[formulajoe]

i mean, that's the answer to the question right?