A spherical capacitor is made from the two concentric spherical conducting shells separated by air. The Inner sphere consists of radius a = 5 cm and outer has radius b = 10 cm. The capacitor is charged to the potential difference V = 90 V.

i) Determine the capacitance of the capacitor.

ii) Determine the charge collected in the outer surface?

iii) Determine the stored energy in the capacitor?

iv) Determine the average energy density (stored energy per unit volume) in the capacitor?