The core loss of a single phase, 230/115 V, 50Hz power transformer is measured from 230V side by feeding the primary (230V side) from a variable voltage frequency source while keeping the secondary open circuited. The core loss is measured to be 1050 W for 230V, 50Hz input. The core loss is again measured to be 500W for 138V, 30Hz input. The hysteresis and eddy current losses of the transformer for 230V, 50Hz input are respectively,

An open circuit test is performed on 50Hz transformer, using variable frequency source and keeping V/f ratio constant, to separate its eddy current and hysteresis losses. The variation of core loss/frequency as function of frequency is shown in the figure The hysteresis and eddy current losses of the transformer at 25Hz respectively are

It is desired to measure parameters of 230V / 115V, 2kVA, single-phase transformer. The following watt-meters are available in a laboratory:

: 250V, 10A. Low Power Factor

: 250V, 5A. Low Power Factor

: 150V, 10A. High Power Factor

: 150V, 5A. High Power Factor

The watt-meters used in open circuit test and short circuit test of the transformer will respectively be

The percentage impedance of a 100 kVA, 11 kV/400V, delta/wye, 50Hz transformer is 4.5%. For the circulation of half the full load current during short circuit test, with low voltage terminals shorted, the applied voltage on the high voltage side will be ________.         

A 4 kVA, 50 Hz, single-phase transformer has a ratio 200/400V. the data taken on the l.v. side at the rated voltage show that the open circuit input wattage is 80W. The mutual inductance between the primary and the secondary windings is 1.91H. What value will be the current taken by the transformer, if the no-load test is conducted on the h.v. side at rated voltage? Neglect the effect of winding resistance and leakage reactances.