A 100 KVA transformer has Its maxi- mum efficiency of 98%. at full load, and unity power factor during the day. it is loaded as follows: LM (@) 12 Hrs - 20 KW at a power factor of 0.5 lagging. (6) 6 Hrs - 20KW at a pof. of 0.9 lagging. (9) 6 Hrs - 20 kW at a p.f. of 0. B lagging all day efficiency" of calculating the all day e the transformer.