Definition:Impedance of Free Space

Definition
Impedance of free space is a physical constant relating the magnitudes of the electric and magnetic fields of electromagnetic radiation travelling through a vacuum.

It is defined as:
 * the quotient of the magnitudes of the electric field and magnetic fields of electromagnetic radiation travelling through a vacuum:
 * $\dfrac {\size {\mathbf E} } {\size {\mathbf H} }$


 * the vacuum permeability multiplied by the speed of light:
 * $\mu_0 c$


 * the square root of the quotient of the vacuum permeability by the vacuum permittivity:
 * $\sqrt {\dfrac {\mu_0} {\varepsilon_0} }$