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

Related Mcqs:

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

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

2. For given applied voltage, with the increase in frequency of the applied voltage?

   A. eddy current loss will decrease
   B. eddy current loss will increase
   C. eddy current loss will remain unchanged
   D. none of the above

3. The no load current in a transformer lags behind the applied voltage by an angle of about_____________?

   A. 180°
   B. 120″
   C. 90°
   D. 75°

4. 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

5. 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

6. 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

7. 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

8. When a given transformer is run at its rated voltage but reduced frequency, its____________?

   A. flux density remains unaffected
   B. iron losses are reduced
   C. core flux density is reduced
   D. core flux density is increased

9. Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is_________________?

   A. approximately equal to one
   B. less than one
   C. great than one
   D. none of the above

10. Reduction in core losses and increase in permeability are obtained with transformer employing__________?

    A. core built-up of laminations of cold rolled grain oriented steel
    B. core built-up of laminations of hot rolled sheet
    C. either of the above
    D. none of the above