The electric constant ($\backslash varepsilon\_0$) is the permittivity of vacuum, a physical constant, defined by:

$\backslash varepsilon\_0\; =\; \backslash frac\{1\}\{\backslash mu\_0c^2\}$

$\backslash mu\_0$ - magnetic constant

$c$ - speed of light

In SI units, the value is exactly expressed by:

$\backslash varepsilon\_0$ = 2.781 625 140 131 510 166 480 1 · π^-1 · 10^-11 F / m

References

Physical constants | Vacuum

Constante électrique