2 capacitors in series w/ a dielectric.

[Iron Charioteer]

Two capacitors (lets call them C₁ and C₂) in series are connected to a voltage source and charged. While still connected to the source one of them is filled with a dielectric (lets say C₂ is filled). I know the charge on C₂ will change by a factor of K because the source keeps the potential differences of each capacitor constant. But does the charge of the unfilled capacitor (C₁) change?
This is more of a conceptual question.

EDIT: I got it. The charge on the unfilled capacitor remains the same.
I would delete the thread but i can't figure out how to do that.

 

[mfb]

I know the charge on C₂ will change by a factor of K because the source keeps the potential differences of each capacitor constant.

It doesn't, it keeps the sum of the potential differences constant.

The charge on the unfilled capacitor remains the same.

It does not.
Changing the charge on one capacitor but not on the other would violate charge conservation.

 

[Iron Charioteer]

Hmmm... I guess i didn't know what i thought i knew. Haha!
So what you're saying is that the the charge on each capacitor remains the same but the potential difference of the capacitors changes; i.e.
V_total=V₁+V₂=q/C₁+q/KC₂.
So the rule for capacitors in series holds even when a dielectric is inserted into one of the capacitors?

 

[mfb]

So what you're saying is that the the charge on each capacitor remains the same

I'm not saying that.

So the rule for capacitors in series holds even when a dielectric is inserted into one of the capacitors?

They apply before and afterwards separately, sure. They'll give different results, however.