Magnetism SI Units

In order to provide a closer relation between practical units for electricity and magnetism, these mks units were standardized in 1960 by international agreement.  The abbreviation is SI, for system International .  Table lists the magnetic SI units.  The corresponding electrical SI units include the coulomb, which is used for both electric flux and charge, the ampere for current, the volt for potential, and the ohm for resistance.  The Henry unit for inductance and the farad unit for capacitance are also SI (System International ) units.

In below table note that the reciprocal of resistance is permeance, corresponding to conductance as the reciprocal of resistance.  The SI unit for conductance is the siemens (S), equal to 1/Ω.  This unit is named after Ernst von Siemens, a European inventor.

As another comparison, the permeability μ of a magnetic material with magnetic flux corresponds to the electric permittivity of an insulator to concentrate electric flux.

INTERNAL SYSTEM OF MKS UNITS (SI) FOR MAGNETISM

Quantity

Symbol

Unit

Flux Φ Weber (Wb)
Flux density B Wb/m2 = tesls (T)
Potential mmf Ampere-turns (A·t)
Field Intensity H Ampere-turns per meter (A·t/m)
Reluctance Ρ = 1/R Weber per ampere turns (Wb/ A·t)
Relative μ μ r or Km None
Permeability μ = μr × 1.26 × 10-6 B/H = tesla(T)/ A·t/m
     

Comments are closed.

x
Sign up for our Newsletter

Enter your email and stay on top of things,