A 3-kVA, 220:110-V, 60-Hz, single-phase transformer yields these test data:
• Open-circuit test: 200 V, 1.4 A, 50 W
• Short-circuit test: 4.5 V, 13.64 A, 30 W
Determine the efficiency when the transformer delivers a load of 2 kVA at 0.85 power factor lagging.