Does the charge of a capacitor change during immersion?

[halo168]

If given a capacitor with stored charge, would its charge remain constant before and after it is immersed in a liquid (i.e. distilled water)? Why?

I know that before immersion, the capacitance would be = (ɛAV/d), but would that be the same if immerged in distilled water?

 

[anorlunda]

If you are asking theoretically without regard to practical realities, then the charge can't change unless there is a current in or out. The capacitance can change, but not the charge if there is no place for the charge to go.

In real life, there are nonzero leakage currents that negate that answer.

 

[berkeman]

If given a capacitor with stored charge, would its charge remain constant before and after it is immersed in a liquid (i.e. distilled water)? Why?

I know that before immersion, the capacitance would be = (ɛAV/d), but would that be the same if immerged in distilled water?

It looks like you are combining two equations...

Q=CV
C=εA/d

When you immerse the capacitor that has nothing between the plates in distilled water, assuming no leakage current, the charge on the plates will not change. So what happens in the first equation? ε changes (by how much?) in the 2nd equation, so what does that do to the first equation?

And since the energy stored in the capacitor is E=CV^2/2, is there a change in the energy stored in the system? If so, where did the extra energy come from or go to?

 

[lekh2003]

I think what you are referring to is the capacitance changing. A very important rule regarding capacitors is that charge is always conserved (unless actively changed by a current or voltage). While the charge is always conserved, capacitance can change and voltage as well. The capacitance and voltage might go up or down when immersed, but never the charge.