The no load current in a transformer lags behind the applied voltage by an angle of about_____________?
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°
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°
A common method of cooling a power transformer is_______________? A. natural air cooling B. air blast cooling C. oil cooling D. any of the above
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
Efficiency of a power transformer is of the order of________________? A. 100 per cent B. 98 per cent C. 50 per cent D. 25 per cent
Which winding in a transformer has more number of turns ? A. Low voltage winding B. High voltage winding C. Primary winding D. Secondary winding
Primary winding of a transformer________________? A. is always a low voltage winding B. is always a high voltage winding C. could either be a low voltage or high voltage winding D. none of the above
A transformer cannot raise or lower the voltage of a D.C. supply because_______________? A. there is no need to change the D.C. voltage B. a D.C. circuit has more losses C. Faraday’s laws of electromagnetic induction are not valid since…
A transformer transforms__________________? A. voltage B. current C. power D. frequency
In the transformer following winding has got more cross-sectional area______________? A. Low voltage winding B. High voltage winding C. Primary winding D. Secondary winding
While conducting short-circuit test on a transformer the following side is short circuited? A. High voltage side B. Low voltage side C. Primary side D. Secondary side