Interactive Learning Tool for AC Circuits
Inductive reactance is the opposition to current change caused by an inductor in AC circuits. As frequency increases, the inductor opposes current flow more strongly.
Where: f = Frequency (Hz), L = Inductance (H)
Units: Ohms (Ω)
✓ Increases with frequency
✓ Directly proportional to both frequency and inductance
✓ At DC (0 Hz), inductive reactance is zero
Capacitive reactance is the opposition to voltage change caused by a capacitor in AC circuits. As frequency increases, the capacitor allows current to flow more easily.
Where: f = Frequency (Hz), C = Capacitance (F)
Units: Ohms (Ω)
✓ Decreases with frequency
✓ Inversely proportional to both frequency and capacitance
✓ At DC (0 Hz), capacitive reactance is infinite
Resonance occurs at the frequency where inductive reactance equals capacitive reactance (XL = XC). At this point, the reactive components cancel each other out.
Where: L = Inductance (H), C = Capacitance (F)
Units: Hertz (Hz)
✓ At resonance, XL = XC
✓ Circuit impedance is purely resistive
✓ Maximum current flow in series LC circuits
✓ Used in tuning circuits, filters, and oscillators
At resonance, XL = XC = 316.23 Ω
Adjust the inductance and capacitance values to see how reactance changes with frequency. The intersection point shows the resonant frequency.
Resonant Frequency: 503.29 Hz
Simple LC circuit showing the interaction between inductance and capacitance at resonance.
• The inductive and capacitive reactances are equal and cancel each other
• Circuit impedance is at minimum (purely resistive)
• Current is at maximum
• Energy oscillates between the magnetic field (L) and electric field (C)