4-16.A 75-kVA, 230-V/115-V, 60-Hz transformer was tested with these results: open-circuit test:115 V, 16.3. A, 750 W; short-circuit test: 9.5 V, 326 A, 1200 W Determine the a. Equivalent impedance

in high-voltage terms. b. Equivalent impendace in per unit. c. Voltage regulation at rated load, 0.8 power factor lagging. d. Efficiency at rated load, 0.8 power factor lagging and at half-load, unity power factor. e. Maximum efficiency and the current at which it occurs.