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
Related Mcqs:
- The full-load copper loss of a trans¬former is 1600 W. At half-load, the copper loss will be___________?
A. 6400 W
B. 1600 W
C. 800 W
D. 400 W - 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 - 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 - If the supply frequency to the transformer is increased,”the iron loss will__________?
A. not change
B. decrease
C. increase
D. any of the above - Iron loss of a transformer can be measured by____________?
A. low power factor wattmeter
B. unity power factor wattmeter
C. frequency meter
D. any type of wattmeter - 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 - 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 - 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 - 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 - 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
