A parallel-plate capacitor with square plates of side length L L\,L and plate separation d d\,d has air between its plates, giving a capacitance CCC.
A second capacitor has square plates of side length 3L and a plate separation of 4d4d4d. The gap between these plates is completely filled with a dielectric material of relative permittivity εr=8\varepsilon_r = 8εr=8.
What is the capacitance of this second capacitor in terms of CCC?
4.5C4.5C4.5C
6C6C6C
18C18C18C
72C72C72C
