Transformers Set 1

provide support to windings ✘ reduce hysteresis loss ✘ decrease the reluctance of the magnetic path ✘ reduce eddy current losses ✔

output voltage fluctuation from no load to full load is least ✘ output voltage fluctuation with power factor is least ✘ difference between primary and secondary voltage is least ✘ difference between primary and secondary voltage is maximum ✔

transformers will be overheated ✘ power factors of both the transformers will be same ✘ parallel operation will be not possible ✘ 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 ✔

copper loss = iron loss ✘ copper loss < iron loss ✘ copper loss > iron loss ✘ none of the above ✔

auto-transformers ✘ air-cooled transformers ✘ welding transformers ✘ oil cooled transformers ✔

6400 W ✘ 1600 W ✘ 800 W ✘ 400 W ✔

frequency ✘ area of the core ✘ flux density of the core material ✘ (A) and (B) both ✔

There is no need to change the D.C. voltage ✘ A D.C. circuit has more losses ✘ Faraday's laws of electromagnetic induction are not valid since the rate of change of flux is zero ✘ None of the above ✔

Core loss ✘ Friction loss ✘ Eddy current loss ✘ Hysteresis loss ✔

iron core ✘ copper winding ✘ winding insulation ✘ frame or case ✔