The change in energy stored in the electric field will just be that corresponding to removing a volume \(\left(d_{1} w\right) \delta x\) of dielectric-free space where the field is E 0 Volts/m and rep...The change in energy stored in the electric field will just be that corresponding to removing a volume \(\left(d_{1} w\right) \delta x\) of dielectric-free space where the field is E 0 Volts/m and replacing it with the volume (wd) \(\delta\)x of dielectric material subject to the field E 2 plus the vacuum volume \(w\left(d_{1}-d\right) \delta x\) subject to the field E 1 . This change in energy will be independent of the exact shape of the end of the slab providing that the extent of the non-un…