A 400KVA transformer has a primary winding of resistance of 0.5 ohm and a secondary winding resistance of 0.001 ohm. the iron loss is 2.5 KW and the primary and secondary voltage are 5KV and 320V volt respectively. if the power factor of the load is 0.85, determine the efficiency of the transformer:
a- on a full load
b- on half load
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