The insulating layer between the plates of a capacitor not only holds the plates apart to prevent conducting contact but also has a big effect on charging. Consider two capacitors whose only...

The insulating layer between the plates of a capacitor not only holds the plates apart to prevent conducting contact but also has a big effect on charging. Consider two capacitors whose only difference is that capacitor number 1 has nothing between the plates, while capacitor number 2 has a layer of plastic in the gap (Figure 20.64). They are placed in two different circuits having similar batteries and bulbs in series with the capacitor.

A more extensive analysis shows that this trend holds true for the entire charging process: the capacitor containing an easily

polarized insulator ends up with more charge on its plates. The capacitor you have been using is filled with an insulator that

polarizes extremely easily.