Editing Velocity factor (section)

===Electric wave===
VF equals the [[reciprocal (mathematics)|reciprocal]] of the [[square root]] of the [[dielectric constant]] ([[relative permittivity]]), <math>\kappa</math> or <math>\epsilon_\mathrm{r}</math>, of the material through which the signal passes:

:<math>\mathrm{VF} = { \frac{1}{\sqrt{\kappa}} } \ </math>

in the usual case where the [[Permeability (electromagnetism)#relative permeability|relative permeability]], <math>\mu_\mathrm{r}</math>, is 1. In the most general case:

:<math>\mathrm{VF} = { \frac{1}{\sqrt{\mu_\mathrm{r}\epsilon_\mathrm{r}}} } \ </math>

which includes unusual magnetic conducting materials, such as [[Ferrite (magnet)|ferrite]].

The velocity factor for a lossless [[transmission line]] is given by:

:<math>\mathrm{VF} = { \frac{1}{c_\mathrm{0}\sqrt{L'C'}} } \ </math>

where <math>L'</math> is the distributed [[inductance]] (in [[henries]] per unit length), <math>C'</math> is the [[capacitance]] between the two conductors (in [[farads]] per unit length), and <math>c_\mathrm{0}</math> is the speed of light in vacuum.