24.12 0 A spherical capacitor is formed from two concentric, spheri- cal, conducting shells separated by vacuum. The inner sphere has ra- dius 15.0 cm and the capacitance is 116 pF. (a) What is the radius of the outer sphere? (b) If the potential difference between the two spheres is 220 V, what is the magnitude of charge on each sphere? 24.26 0- A parallelplate vacuum capacitor has 8.38 J of energy stored in it. The separation between the plates is 2.30 m. If the separation is decreased to 1.15 mm, what is the energy stored (a) if the capacitor is disconnected from the potential source so the charge on the plates re mains constant, and (b) if the capacitor remains connected to the potential source so the potential difference between the plates remains constant