Which of the following is not a factor in determining impedance in an AC circuit?

Impedance in an AC circuit is a combination of resistance and reactance, and it is influenced by several factors, most notably frequency, which affects reactance, and phase angle, which indicates how the voltage and current are related over time.

The reason frequency is a critical factor is that it directly determines the inductive and capacitive reactance in the circuit. For example, in inductive circuits, the inductive reactance increases with frequency, while in capacitive circuits, the capacitive reactance decreases with increasing frequency.

Voltage and current are not variables that directly influence impedance; instead, they are results of the impedance in the circuit. The relationship of voltage and current through Ohm's Law (V = IR) is fundamentally established based on the impedance present, but they do not alter the impedance itself.

Therefore, identifying frequency as a factor while voltage and current serve merely as manifestations of the effects of impedance helps clarify why it stands out in this context. Phasor analysis indicates that phase angle will also contribute to how voltage and current interact, making it another relevant factor in impedance calculations.

Overall, emphasizing frequency's role in affecting reactance and impedance highlights why it is essential, while voltage and current are outcomes of the impedance relations