Question

In the network shown in Fig. find the value of load to be connected across terminals AB consisting of variable resistance R_L and capacitive reactance X_C which would result in maximum power transfer.

Answer 1

We will first find the Thevenin’s equivalent circuit between terminals A and B. When the load is removed , the circuit become as shown in Fig..

V_th = drop across (2 + j10) = 50 ∠45º × (2 + j10)/(7 + j10)

= 41.8 × 68.7º = 15.2 + j 38.9 R_th = 5 | | (2 + j 10) = 4.1∠23.7º = 3.7 + j 1.6

The Thevenin’s equivalent source is shown in Fig. 

Since for MPT, conjugate match is required hence, X_C = 1.6 Ω and R_L = 3.7 Ω