Op-Amps and General Points.

[(*steve*)]

That is simplistic. The impedance of a capacitor decreases with increasing frequency. (impedance is like resistance + reactance)

Higher value capacitors have an impedance that is lower at any given frequency than that of a lower value capacitor (in theory).

Practically speaking there are other issues, but they are due to real capacitors not being perfect.

Wikipedia has enough mathematics describing this to keep you up all night.

This may be of more practical interest at your current level.

 

[jkele]

Oh look i know that the impedance of a capacitor is 1/jwC where C = Capacitance, w = frequency in radians. I mentioned that point because you said it blocks DC.

 

[(*steve*)]

OK, It's hard to know what you do and don't know. Please excuse me if I cover stuff you already know, and ask for more explanations where I gloss over stuff.

But also be careful of using terms like "short circuit" if you know they don't apply.