A. primary turns to secondary turns
B. secondary current to primary current
C. secondary induced e.m.f. to primary induced e.m.f
D. secondary terminal voltage to primary applied voltage
Related Mcqs:
- If R2 is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary will be___________?
A. R2/VK
B. R2IK2
C. R22!K2
D. R22/K - 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 - 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 - 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 the rate of change of flux is zero
D. none of the above - 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° - 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 - A transformer can have zero voltage regulation at______________?
A. leading power factor
B. lagging power factor
C. unity power factor
D. zero power factor - If a transformer is switched on to a voltage more than the rated voltage______________?
A. its power factor will deteriorate
B. its power factor will increase
C. its power factor will remain unaffected
D. its power factor will be zero - 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
