a) The primary of such transformers is energized for all twenty-four hours and core losses occur throughout the day whereas copper losses will occur only when secondary is supplying load
b) Core losses are always more than copper losses
c) Core losses may destroy the insulation
d) Core losses will heat up the oil of the transformer rapidly
Ans: (a)
a) The percentage impedance should be equal
b) The transformers should be properly connected with regard in polarity
c) The primary winding of the transformers should be suitable for the supply system voltage and frequency
d) The voltage ratings of transformers of primary and secondary winding should be identical
Ans: (a)
a) Parallel operation will not be possible
b) Parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load
c) Transformers will be over heated
d) Power factors of both of the transformers will be same
Ans: (b)