Hi, I found something quite interesting about resistance in my book. It says that at high frequency (MHz scale), resistance R decreases due to "inductance L" and "capacitance C" characteristics of resistor. So the resistor can be modeled as (Ro in series with L) // C (Ro denote the resistance in the model as to distinguish from R, which is the real effective resistance). The model can explain mathematically why R decreases when frequency f increases. However, what I'm concerned about is the nature of the phenomenon. In any geometry of the resistor, there should be magnetic field, and that accounts for L. But if the resistor is just a straight wire, not a coil, how should we explain the existence of C? Besides, is there any paper or text analyzing this effect theoretically? Thank you very much.