Two solid disks with a radius of R₀ = 12 cm and a separation of 8.0 mm form a parallel plate capacitor. An 18 V power supply is connected to the disks. After an infinitely long time, the wires are disconnected while the charge on the disks is conserved. After disconnecting the power supply, the radius of the disks is changed to 1.5R₀. Calculate i) the charge stored on the disks, ii) the electric field strength between the disks, and iii) the potential difference between the electrodes at the separation 1.5R₀.