College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 44

The voltage across an air-filled parallel-plate capacitor is measured to be 85.0 V. When a dielectric is inserted and completely fills the space between the plates as in Figure P16.49, the voltage drops to 25.0 V. (a) What is the dielectric constant of the inserted material Can you identify the dielectric (b) If the dielectric doesn't completely fill the space between the plates, what could you conclude about the voltage across the plates