Assume that the object modeled is moving with a constant velocity, v =
v0. The equations now take on a slightly different form that includes the Galilei invariant versions of the electromagnetic fields. The term Galilei invariant is used because they remain unchanged after a coordinate transformation of the type
The electromotive intensity is the most important of these invariants. The Lorentz magnetization is significant only in materials for which neither the magnetization M nor the polarization
P is negligible. Such materials are rare in practical applications. The same holds for the magnetization term of the magnetomotive intensity. Notice that the term
ε0v ×
E is very small compared to
B/
μ0 except for cases when
v and
E are both very large. Thus in many practical cases this term can be neglected.
The terms containing v ×
B cancel out, which yields the following equation:
The magnetization M and the polarization
P occur explicitly in this expression.