Question 1 The figure shows a parallel plate capacitor, where the top plate is positively charged and the bottom plate is negatively charged. There are three different dielectrics, with thickness t, t2 and t3 and dielectric constant K, K2 and 3 respectively. As shown, t+t2 + t3 = d. All the dielectric plates have the same area A as the capacitor plates. a Using the idea of electric dipole and polarization vector, find the net electric field inside a dielectric material as a function of external electric field Eo and K. b Calculate the potential difference between the upper and lower plate of the capacitor and hence find the capacitance. c If K=k=K3=1, then show whether this configuration is equivalent to a parallel plate capacitor with no dielectric inside. 5 6+2 3