OFFSET
3,1
COMMENTS
Denoted Z_0, this is a function of assigned metrological constants. Regarding these, see A003678 for general context notes, references and links. - Stanislav Sykora, Jun 16 2012
LINKS
FORMULA
Z_0 = [magnetic_permeability_of_vacuum]*[speed_of_light_in_vacuum] = 10^-6 * A019694 * A003678 = Pi * 119.9169832 Ohms, where 119.9169832 = 4*10^-7 * 299792458 (exact value). [The 2nd equality is valid only for the SI definition that was in effect until 2019.]
Equals 2*alpha*h/e^2, where alpha is the fine-structure constant, h is the Planck constant and e is the elementary charge. The decimal expansion of Z_0 in SI units after the redefinition in 2019 is 2*A003673*A003676/A081823^2. - Jianing Song, Nov 25 2023
EXAMPLE
376.730313 ... Ohm [also kg * m^2 * s^-3 * A^-2].
MATHEMATICA
RealDigits[4*Pi*10^-7*299792458, 10, 105] // First (* Jean-François Alcover, Mar 07 2014 *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Stanislav Sykora, Jun 16 2012
EXTENSIONS
Edited by Andrey Zabolotskiy, Aug 12 2020
STATUS
approved