Two parallel plate capacitors A and B have the same separation d=`8.85xx10^-4m` between the plates. The plate area of A and B are `0.04m^2 and 0.02m^2` respectively. A slab of dielectric constant (relative permittivity) K=9 has dimensions such that it can exactly fill the space between the plates of capacitor B.
A is then charged to a potential difference of 110V. Calculate the capacitance of A and the energy stored in it.