The electric field in the dielectric then corresponds
to the case when the net surface charge density on the plates is ±(s – sp) That is,
0
P
E
σ
σ
−ε
=
(2 47)
so that the potential difference across the plates is
0
P
V
E d
d
σ
σ
−ε
=
=
(2 48)
For linear dielectrics, we expect sp to be proportional to E0, i