The 3-single phase step-up transformers rated at 10MVA, 4.6kV/13.8kV are joined in Wye-Delta configuration. The three transformers are employed to feed a 20MVA load at 0.9 p.f. with an efficiency of 96 percent. By using per unit system, compute:
1. The secondary line voltage.
2. The primary and secondary line currents when supplying the load.