- #1

Amir H.Saba

- 2

- 0

as you know according to ampere's law ∫B.dl=μ

_{0}I

but why μ

_{0}that appears in Maxwell's equations is

__exactly__4π *10

^{-7}?

for example in electric field ε

_{0}is 8.85 *10

^{-12}

and μ

_{0}like ε

_{0}is a constant that is related to material properties and why this constant is a special number as π that B is special ?