Dielectrics

Typically, the space between the two plates of a Capacitor is a vacuum. Thus, we use vacuum permittivity in our equations.

By inserting a insulator between the plates, we can increase the Capacitance of the Capacitor. For this new material, we use instead.

A Dielectric is the insulator used.

Say we have a parallel plate capacitor:

Then, we use a dielectric:

However, is still useful for manipulating this equation with other equations. So, we use a dielectric constant , which gives in terms of .

Note that since is always greater than 1, the capacitance has increased by a factor of .

Where is the old capacitance.