You'll find this
constant, also known as the "
magnetic constant" in a lot of
magnetic equations. It is a constant of
proportionality that exists between
magnetic induction and
magnetic field intensity.
In
SI units, the value of this
constant is
4π x 10-7 Hm-1
Please note that the constant may be much different in other materials. This is the
free space value.
It is related to the electric constant (the
permittivity of free space, ε
0) by
ε0μ0 = 1/c2
where
c is the
speed of light.