Notes

Different Cases…

Different Cases –
Case I : When AC circuit contains ohmic resistance. In this case, ɸ = 0. ∴ cosɸ = 1 ⇒ P_ev = V_rms × I_rms = V_rms = V_rms × V_rms/R = V²_rms/R,
Case II : When AC circuit contains only capacitor. In this case, ɸ = -π/2 ∴ cosɸ = cos(-π/2) = 0 ⇒ P_av = 0
Case III : When AC circuit contains only inductance. In this case, ɸ = π/2 ⇒ cosɸ = cosπ/2 = 0
Case IV : When AC circuit contains resistance and capacitance both. P_av = V²_rms R/(R² + 1/⍵² C²)
Case V : When AC circuit contains resistance and inductance both. P_av = V²_rms R/(R² + ⍵L²)
Case VI : When AC circuit contains inductance, capacitance and resistance. P_av = V²_rmsR/R² + (⍵L – 1/⍵C)²