The opposition offered by a capacitance to an AC current is termed capacitive reactance and depends on the capacitance and also the AC frequency. The next formula is used to calculate the capacitive reactance of a capacitor in an AC circuit.
Formula 1
Where:
Xc is the capacitive reactance in ohm (Ω)
Π is 3,1416 – constant
f is the frequency iun hertz (HZ)
C is the capacitance in farads (F)
Derivated Formulas:
Formula 2
Formula 3
Application Example:
A 0,2 µF (200 nF) capacitor is operating in a 100 kHz circuit. Calculate the reactance at that frequency.
Data:
C = 0,2 µF = 0,2 x 10-6 F
F = 100 kHz -= 100 x 103 Hz
Xc = ?
Applying formula 1:
Xc = 1 / 1,256
Xc= 0,79 Ω
