Assume the 8-Q resistor is the load in the circuit. Assumevg = 110 V rms and a variable turns ratio of 1 : n. Find

a. The maximum power dissipated by the load.

b. The maximum power absorbed from the source.

c. The power transfer efficiency.

winding resistance and inductance, respectively, and rc and Lc represent the losses in the core of the transformer and the inductance of the core. The ideal transformer is also included in the model.

With the open-circuit test, we may assume that  I˜P = I˜S = 0. Then all the current that is measured is directed through the parallel combination of rc and Lc .

We also assume that |rc || jωLc | is much greater than rw + jωLw . Using these assumptions and the open-circuit test data, we can find the resistance rc and the inductance Lc .

In the short-circuit test, we assume that V˜ secondary is zero, so that the voltage on the primary side of the ideal transformer is also zero, causing no current flow through the rc - Lc  parallel combination. Using this assumption with the short-circuit test data, we are able to find the resistance rw and inductance Lw .

Using the following test data, find the equivalent circuit of the transformer:

The transformer is a 460-kVA transformer, and the tests are performed at 60 Hz.