Using what you have learned constructing the phasor diagram for the LRC series circuit, construct  a diagram for the LRC parallel circuit. Derive an expression for the circuit impedance Z and the  phase angle φ between the applied emf and the current supplied by the emf.  HINT: in the series circuit, the current through all four components was the same. Ask yourself  what the components in this arrangement have in common.

Which one of the following statements is true: The purpose of the power-factor correction is to add inductive elements to keep real power at a minimum level. The purpose of the power-factor correction is to add resistive elements (typically resistances) to improve the total reactive power. The purpose of the power-factor correction is to add reactive components (typically capacitive) to establish a system power factor closer to unity. The purpose of the power-factor correction is to add resistive elements (typically resistances) to establish a system power factor closer to zero.

An impedance z₁ = 8j5ohms is in parallel with an impedance z₂ = 3 + j7ohms. If 100V are imposed on the parallel combination. Find the branch current 11, 12 and the resultant current. Draw the corresponding phasor diagram showing each current and voltage drop across each parameter. Calculate also the equivalent resistance, reactance and impedance of the whole circuit.

Impedances Z1 = 5.83 at angle of -59 deg. and Z2 = 8.94 at an angle of 63.43 deg. are in series and carry an effective current of 5A. Determine the Power and power factor of the circuit indicating if it is leading or lagging.