# Partially Filled Capacitor#

A parallel-plate capacitor with only air between its plates is charged by connecting the capacitor to a battery. The capacitor is then disconnected from the battery, without any of the charge leaving the plates.

## Part 1#

A voltmeter reads 45.0 $$\textrm{ V}$$ when placed across the capacitor. When a dielectric is inserted between the plates, completely filling the space, the voltmeter 20.0 $$\textrm{ V}$$. What is the dielectric constant of the material?

## Part 2#

What will the voltmeter read if the dielectric is now pulled away out so it fills only $$1/$$3 of the space between the plates?