A parallel-plate capacitor with only air between the plates is charged by connecting it to a battery. The capacitor is then disconnected from the battery, without any of the charge leaving the plates.
A) A voltmeter reads 46.0V when placed across the capacitor. When a dielectric is inserted between the plates, completely filling the space, the voltmeter reads 14.5V . What is the dielectric constant of this material?
B) What will the voltmeter read if the dielectric is now pulled partway out so it fills only one-third of the space between the plates?