For the circuit of Fig P970 with ZA ZB and ZC loads specifie

For the circuit of Fig. P9.70 with Z_A, Z_B and Z_C loads specified as follows: Z_A: P = 2kW at Pf = 0.8 lagging Z_B: P = 3kW at Pf = 0.6 leading Z_C: P = 1.5 kW and Q = 500Var Find the power factor at terminal \"ab\". Assume omega = 6000 Rad/s, V_m = 10 V, theta_v = 15 A, I_m = 15 A, and theta_i = 50 degree.

Solution

cos(15-50) = 0.819 (lead)