# A single-phase transformer rated 1 .2 kV / 120 V, 7.2 kV A has primary-referred parameters At…

A single-phase transformer rated 1 .2 kV / 120 V, 7.2 kV A has primary-referred parameters At rated voltage its core loss may be assumed to be 40 W for all values of the load current. (0) Determine the eA1cicncy and regulation of the transformer when it delivers 7.2 kVA at V2 o c 120 V and power factor of (i) 0.8 lagging and ( ii) 0.8 leading. (b) for a given load voltage and power factor it can be shown that the efficiency of transformer Litanies its maximum value at the kVA load level which makes t he IR winc Jing losses equal to t l t e core loss. Using this result, determine the maximum efficiency of the above transformer at rated voltage and 0.8 power factor, and the kV A load level at which it occurs