1. A two winding transformer is rated at 50 kVA. The maximum efficiency of the transformer occurs when the output of the transformer is 35 kVA. Find the rated efficiency of the transformer at 0.8 PF lagging given that the no load losses are 200 w.
2. The no-load input to a 5 kVA, 500/100-V, single-phase transformer is 100 W at 0.15 PF at rated voltage. The voltage drops due to resistance and leakage reactance are 0.01 and 0.02 times the rated voltage when the transformer operates at rated load. Calculate the input power and power factor when the load is 3 kW at 0.8 PF lagging at rated voltage.