Final answer:
The peak voltage is the maximum voltage reached during each alternation of an AC signal. For a 120-V RMS AC supply, this would be approximately 170 V. RMS voltage provides a measure of the effective voltage in AC circuits.
Step-by-step explanation:
The 'highest voltage your current reach during each alternation' refers to the peak voltage of an alternating current (AC) signal. For a typical 120-V AC power supply in the United States, the peak voltage can be calculated using the relationship between the root mean square (RMS) voltage and the peak voltage, which is Vpeak = Vrms × √2. Using this formula, a 120 V RMS AC supply would have a peak voltage of approximately 170 V. Note that RMS voltage is a measure of the effective voltage and power handling of AC circuits, whereas the average voltage for a sinusoidal AC signal over one complete cycle is zero because the positive and negative alternations cancel each other out. The minimum voltage occurs twice every cycle and is at 0 V, at the moment when the current transitions from positive to negative, or vice versa.