This is one of those things about AC. In every case we must be aware which we're considering, whether a) peak voltage, or b) RMS voltage.
That's only part of the issue. In any case, we usually measure impedance by passing current through the component and then read what voltage develops. If we set it to 1 Ampere, then the voltage we read across the component is automatically equal to the component's impedance. Because V=A*R.
One Amp does no harm to virtual components even though we rarely do that to real hardware.