Consider a parallel plate capacitor, with plate area A$,$ plate separation d$,$ and dielec tric constant K of the material between the plates. $($a$)$ Evaluate the capacitance if A $=100$cm$2,$ d $=1$ mrn$,$ and K $=120.($b$)$ If the potential difference between the plates is $6$ V$,$ calculate the energy of the capacitor. $[$Answer: U $=1\mathrm{.}9$ x $10-7$ J$]$