1. The potential at the center of a 2.0-cm-diameter copper sphere is 500 V, relative to V=0 V at infinity. How much excess charge is on the sphere?
2. Two 2.0 cm x 2.0 cm square electrodes, spaced 0.4 mm apart, are connected to a 10 V battery.
(a) What is the capacitance?
(b) What is the charge on each electrode?