A 100 kva 11 kv231 v transformer has hv and lv winding

Question

A 100 kVA, 11 kV/231 V transformer has HV and LV winding resistances of 8.51 Ω and 0.0038 Ω respectively. It gave the following test results:

Calculate

(a) Equivalent leakage reactance of the transformer

(b) Full load copper loss

(c) Efficiency at full-load and half full-load at 0.85 lagging power factor