i may need your help for following question. 15kva, 2300/230v, 50Hz transformer has voltage drop of 2% and 4% of load voltage, due to winding resistance and leakage reactance respectively, at full load. 230v is maintained at the secondary terminal. The full load copper loss is equal to the iron loss. All parameters are referred to the secondary side. find 1. the primary voltage at full load and unity power factor 2. the half load efficiency at 0.8 power factor lagging. 3. The load power factor at which the voltage regulation would be zero.