
15–110 Electricity and Magnetism
In the following two-part Gedanken experiment, slabs of neutral dielectric material are
immersed in the electric field between two parallel charged plates. In the first part, the slab
occupies only a portion of the volume between the plates, as illustrated in Figure 15.5. In
the second part, the slab completely fills the gap, as shown in Figure 15.6.
The [equal and opposite] electric charge residing upon the parallel plates is externally pre-
scribed and independent of details pertaining to the dielectric. WHEN the dielectric block is
neutral, AND has face area A, precisely matching that of the plates, AND the usual