How is the impedance angle of a capacitor characterized?

The impedance angle of a capacitor is characterized as −90°. This is derived from the relationship between voltage and current in a capacitor. In an ideal capacitor, the current leads the voltage by 90 degrees. This phase difference signifies that while the voltage across the capacitor is at its maximum, the current can already be at its maximum or decrease, thus exhibiting a leading behavior.

In complex impedance representation, the impedance (Z) of a capacitor is given as (Z = \frac{1}{j\omega C}), where (j) is the imaginary unit, (\omega) is the angular frequency, and (C) is the capacitance. The impedance is purely imaginary and has no real component, leading to an angle of −90° when expressed in polar form.

To further clarify, the positive angle signifies that the current lags the voltage, which is typical for inductors; however, for capacitors, this is reversed, resulting in a negative angle. Therefore, recognizing that the impedance angle reflects the phase relationship between current and voltage is crucial in understanding this result.