Points to Remember in Parallel Resonant Circuit

Points to Remember in Parallel Resonant Circuit

1. For any parallel circuit consisting of one L and one C, the power factor is unity at resonance. i.e., reactive part of Z is zero and also reactive part of Y must be zero.

2. For a parallel circuit we prefer to compute Y to Z.

3. The expression for resonant frequency is obtained by equating reactive part of Y (susceptance) to zero.

4. At parallel resonance, the admittance is minimum and hence the impedance is maximum and the current is minimum.

5. For a parallel RLC circuit

(a) f0 = 1/2π√LC

(b) Q = R/ω₀L = ω₀ CR

6. For a parallel practical resonant circuit

(a) f₀ = 1/π × √1/LC – R²/L²

(b) Z = 1/Y = R² + XL² / R = L/CR

 (c) Dynamic impedance, Z_o = L/CR

(d) Current at resonance = ECR / L

(e) Current magnification = ω₀ L / R = Q

7. For a parallel circuit consisting of two circuits, one branch R₁ and L and another branch R₂ and C,