In an AC circuit, the maximum power Pmax is transferred from a source with source impedance Zs = Rs + jXs to a load with load impedance ZL = RL + jXL when:

While calculating Thevenin resistance (Rth) or Norton resistance (RN), independent constant current sources in the circuit are:

While calculating Thevenin resistance (Rth), constant current sources in the circuit are:

According to the Maximum Power Transfer Theorem, maximum power is delivered from a source to a load when the load resistance (RL) is equal to the internal resistance (r) of the source. At this specific condition, what is the efficiency of the power transfer?