A no-load test is performed on a transformer to determine_______________?

Related Mcqs:

1. The no-load current drawn by transformer is usually what per cent of the full-load current ?

   A. 0.2 to 0.5 per cent
   B. 2 to 5 per cent
   C. 12 to 15 per cent
   D. 20 to 30 per cent

2. In an actual transformer the iron loss remains practically constant from no load to full load because:____________?

   A. value of transformation ratio remains constant
   B. permeability of transformer core remains constant
   C. core flux remains practically constant
   D. primary voltage remains constant
   C. secondary voltage remains constant

3. Which of the following is the main advantage of an auto-transformer over a two winding transformer?

   A. Hysteresis losses are reduced
   B. Saving in winding material
   C. Copper losses are negligible
   D. Eddy losses are totally eliminated

4. The changes in volume of transformer cooling oil due to variation of atmospheric temperature during day and night is taken care of by which part of transformer?

   A. Conservator
   B. Breather
   C. Bushings
   D. Buchholz relay

5. No-load on a transformer is carried out to determine______________?

   A. copper loss
   B. magnetising current
   C. magnetising current and loss
   D. efficiency of the transformer

6. In a given transformer for given applied voltage, losses which remain constant irrespective of load changes are______________?

   A. friction and windage losses
   B. copper losses
   C. hysteresis and eddy current losses
   D. none of the above

7. An ideal transformer will have maximum efficiency at a load such that?

   A. copper loss = iron loss
   B. copper loss iron loss
   D. none of the above

8. Which of the following loss in a transformer is zero even at full load ____________?

   A. Core loss
   B. Friction loss
   C. Eddy current loss
   D. Hysteresis loss

9. The maximum load that a power transformer can carry is limited by its________________?

   A. temperature rise
   B. dielectric strength of oil
   C. voltage ratio
   D. copper loss

10. For a transformer, operating at constant load current, maximum efficiency will occur at______________?

    A. 0.8 leading power factor
    B. 0.8 lagging power factor
    C. zero power factor
    D. unity power factor