*65. mmh An empty capacitor has a capacitance of 3.2 µF and is connected to a 12-V battery. A dielectric material (k = 4.5) is inserted between the plates of this capacitor. What is the magnitude of the surface charge on the dielectric that is adjacent to either plate of the capacitor?

(Hint: The surface charge is equal to the difference in the charge on the plates with and without the dielectric.)

 

As before we know the relationships for a capacitor with and without a dielectric are:

Without dielectric

And with a dielectric

 

Now since the battery is connected the voltage is constant.  So we have

 

Since the capacitance changes with a dielectric by

Solving for

So with a dielectric

And without a dielectric

And with a dielectric

 

 

 

 

Please send any comments or questions about this page to ddonovan@nmu.edu

This page last updated on June 11, 2018