# Resolve RDF Terms

Data based on @zazuko/vocabularies
unit:PlanckImpedance
http://qudt.org/vocab/unit/PlanckImpedance

### Namespace

http://qudt.org/vocab/unit/

### Recommended prefix

unit:

lang:en
Planck Impedance
lang:""
The Planck impedance is the unit of electrical resistance, denoted by ZP, in the system of natural units known as Planck units. The Planck impedance is directly coupled to the impedance of free space, Z0, and differs in value from Z0 only by a factor of $$4\pi$$. If the Planck charge were instead defined to normalize the permittivity of free space, $$\epsilon_0$$, rather than the Coulomb constant, $$1/(4\pi\epsilon_0)$$, then the Planck impedance would be identical to the characteristic impedance of free space.
lang:""
http://en.wikipedia.org/wiki/Planck_impedance
lang:""
$$Z_P = \frac{V_P}{I_P}= \frac{1}{4\pi\epsilon_0c}=\frac{\mu_oc}{4\pi}=\frac{Z_0}{4\pi}=29.9792458\Omega$$\where $$V_P$$ is the Planck voltage, $$I_P$$ is the Planck current, $$c$$ is the speed of light in a vacuum, $$\epsilon_0$$ is the permittivity of free space, $$\mu_0$$ is the permeability of free space, and $$Z_0$$ is the impedance of free space.
lang:""
Zₚ