As an illustration of how identification of the induced polarization charge can be used in a…
As an illustration of how identification of the induced polarization charge can be used in a qualitative determination of the fields, consider the fields between the plane parallel electrodes of Fig. P6.6.8. In Fig. P6.6.8a, there are two layers of dielectric.
(a) In the limit where 
is zero, what is the imposed 
?
(b) What is the 
induced by this field at the interface between the dielectrics.
(c) For 
sketch the field lines in the two regions. (You should be able to see, from the superposition of the fields induced by this and that imposed, which of the fields is the greater.)
(d) Now consider the more complicated geometry of Fig. 6.6.8b and carry out the same steps. Based on your deductions, draw a sketch of and E for the case where 
Fig. P6.6.8
