Reactance is similar to resistance but it applies to AC circuits. Reactance usually changes if the frequency changes.

  • Reactance is measured in Ohms
  • Reactance applies to capacitors
  • Reactance applies to inductors
  • Reactance is the same as impedance for a purely capacitative circuit
  • Reactance is the same as impedance for a purely inductive circuit
  • Reactance is a measure of the opposition to current flow due to the capacitor or inductor

Capacitative Reactance Xc

Xc = 1 / 2 π f C

Inductive Reactance XL

XL = 2 π f L

  • f is the frequency of the AC signal in Hertz
  • C is the capacitance in Farads
  • L is the inductance in Henries
  • π is Pi = 3.141 approx