Let \(S=100 \mathrm{~mm}^{2}, d=3 \mathrm{~mm}\), and \(\epsilon_{r}=12\) for a
parallel-plate capacitor.
(a) Calculate the capacitance. (b) After connecting a 6-V battery across the
capacitor, calculate \(E, D, Q\), and the total stored electrostatic energy.
(c) With the source still connected, the dielectric is carefully withdrawn
from between the plates. With the dielectric gone, recalculate \(E, D, Q\), and
the energy stored in the capacitor. \((d)\) If the charge and energy found in
part \((c)\) are less than the values found in part \((b)\) (which you should have
discovered), what became of the missing charge and energy?