So I was playing in NI, with RLC circuits, trying to understand resonance, and what causes it etc. What I did is following: I connected an RLC circuit to a function generator, where I can change my frequency. What I found, that at some frequencies capacitor voltage was above the voltage source's voltage. I couldn't explain that at that moment but then I realised I saw this somewhere. [PLAIN]http://pokit.org/get/3f3d916aa8f70d541b889efc3736b968.jpg [Broken] This overvoltage and undervoltage as I call it, I do not understand. Why does this happen at specific frequency both for capacitor and inductor? I cannot find the google solution for this as I don't know the name of this phenomena in English.