What is the role of a capacitor in improving the power factor of an AC circuit with an inductive load?
**Power factor** cos φ = R/Z, 0≤cos φ≤1, at resonance cos φ=1 maximum power, pure L or C cos φ=0 zero average power, current wattless because energy stored returned. Instantaneous power when current maximum in pure L: I=I_peak, V=0 because V leads 90°, so P= V I =0 at that instant, average zero. An inductive load causes the current to lag the voltage, reducing the power factor. Adding a capacitor in parallel introduces a leading current that counteracts the lagging current, bringing the net phase difference closer to zero, thus improving the power factor. Applying X_L = ωL, X_C = 1/ωC, Z = √(R
Ref: NCERT > Physics Book > Alternating Currents > Power in AC Circuits - Power Factor and Wattless Current