(a) Describe a simple single phase transformer. (6)

(b) A 15 KVA, 440/110-volt, 50Hz cycle/sec, single-phase transformer has primary and secondary resistances of 0.12 ohm and 0.0077 ohm respectively. The iron loss of the transformer is 0.16 kW. Calculate the efficiency of the transformer (10)

(i) On full load unity power factor

(ii) On 80 per cent full load at a power factor of 0.9 lagging