Multiple choice questions on Electrical Machines - 5
Important Multiple Choice Questions On Electrical Machines 1. Supply to one terminal of delta-star three-phase core type transformer which is on no-load fails. Assuming magnetic circuit symmetry, voltages on the secondary side will be 230, 230,115 230,115, 115 345, 115, 115 345, 0, 345 2. A 220/440 V, 50Hz, 5kVA single phase transformer operates on 220V, 40 Hz supply with secondary winding. Then The eddy current loss and hysteresis loss of the transformer decrease The eddy current loss and hysteresis loss of the transformer increase The hysteresis loss of the transformer increases while eddy current loss remains the same The hysteresis loss remains the same whereas eddy current loss decreases 3. The voltage regulation of a large transformer is mainly influenced by No-load current and load power factor Winding resistances and load power factor Leakage fluxes and load power factor Winding resistances and core losses 4. If a sinus...