3. In the circuit shown below, Vs = 20cos(377t). Determine the impedance value Z₁ that would result in maximum real power transfer to the load. Also, determine the value of Pmax. Hint: maximum power transfer occurs when ZL = Zth* 50 w j30 20 ΩΣ -6 ΩΣ a b ZL 3. Determine (by inspection) the bus admittance matrix (Ybus) for the circuit shown below. -j0.50 2/0° V + 1.00 j0.4Q m -j0.20 0.80 0.20 5.00 2 1.00 j0.250 -j0.10 4/30° A