
320 Forensic Engineering Fundamentals
e total power exiting a volume V bounded by a surface S is
s
s
= ×⋅
EH
(10.11)
Since, in general, P is complex, the real part represents the real power density and the
imaginary part represents the reactive power.
Most tables of permittivity and permeability are expressed in terms of the relative per-
meabilities and permittivities with respect to free space. ese are expressed in equation
form as follows:
ε
ε
ε
r
=
(10.12)
µ
µ
µ
r
=
(10.13)
e constitutive parameters for common materials encountered in forensic electrical
investigations are summarized in Tables 10.1 through 10.3. e relative permittivity of ...