# Physics Homework problem: Dielectrics

1. Mar 17, 2009

### Jscrub

I cannot figure out this problem...can someone help me???

A 3500 air-gap capacitor is connected to a 32 battery.

If a piece of mica fills the space between the plates, how much charge will flow from the battery?

2. Mar 18, 2009

### tiny-tim

Welcome to PF!

Hi Jscrub! Welcome to PF!

First, how much charge will flow from the battery when the gap is just air?

Second, what equations do you know about how a dielectric affects a field or a capacitor?

3. Mar 18, 2009

### Jscrub

c= KCo

c=Q/V

Q Air = 1.12E-4

4. Mar 18, 2009

### Jscrub

v= 32 V

K(mica) = 7

K (air) = 1.0006

so, Co= 1.12E-4

5. Mar 18, 2009

### LowlyPion

What is a 3500 air-gap capacitor?

Is that a 3500μf capacitor or 3500nf?

What is the effect of the dielectric on the capacitance?

6. Mar 18, 2009

### Jscrub

The above was not a conclusion..it was just a reply to the previous person...

Co = 3500E-9...

But it is fine..I don't need anymore help...I figured it out...

Thanks