1. An air-filled capacitor is made from two flat parallel plates 1.5 mm apart. The inside area of each plate is 7.9 cm². (a) What is the capacitance of this set of plates? C F air = (b) If the region between the plates is filled with a material whose dielectric constant is 6, what is the new capacitance? C dielectric F

5. A capacitor is charged by a battery. It may or may not have been removed from this battery. A dielectric is then either inserted or removed from between the plates. The capacitance increased by a factor of 5 and the charge across the plates increased by a factor of 5. a. Was the capacitor on or off the battery? Explain. b. Was the dielectric inserted or removed from between the plates? Explain.

1. The plates of an empty parallel-plate capacitor of capacitance 5.5 pF are 2.3 mm apart. What is the area of each plate? A = m²

1. A capacitor is made from two concentric spheres, one with radius 6 cm, the other with radius 8.5 cm. (a) What is the capacitance of this set of conductors? C= F (b) If the region between the conductors is filled with a material whose dielectric constant is 6.5, what is the capacitance of the system? C= F