Dielectric materials

1
Dielectric materials

• Their effect on capacitance.

2
What is a dielectric?

• an insulator

3
Effect on Capacitance

• C is increased
• E is weakened by dielectric
• For a given Q, V is reduced
• C is increased by K.
• K is characteristic of the dielectric

4
Effect of dielectric on E

• Start w/ isolated, charged capacitor
• constant Q
• slide dielectric between plates
• E Eo/K
• C kCo
• e K eo

5
Dielectric introduced while C connected to battery

• battery pumps more Q to maintain constant V
• QKQo

6
Multiple Dielectrics

• Potential difference between the plates is the
  sum of the potential difference across each
  material.