hello! why capacitors and inductors affect the phase of both current and voltage of a AC circuit and resistors don't? let's say we have an AC circuit with resistors only, then there is no change in the voltage and current as imposed from the voltage/current source, right? but what happens when we add a capacitor or inductor? why phase changes? and why voltage phase change and/or current phase change? and we mean change, in comparison to what exactly? please elaborate in simple terms! you may use a mechanical analogue or something! thanks!