A. less than 15 A
B. more than 15 A
C. 15 A
D. none of the above
Related Mcqs:
- 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 - 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 - 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° - No-load current of a transformer has_____________?
A. has high magnitude and low power factor
B. has high magnitude and high power factor
C. has small magnitude and high power factor
D. has small magnitude and low power factor - 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 - Which of the following statements regarding an idel single-phase transformer having a turn ratio of 1 : 2 and drawing a current of 10 A from 200 V A.C. supply is incorrect?
A. Its secondary current is 5 A
B. Its secondary voltage is 400 V
C. Its rating is 2 kVA
D. Its secondary current is 20 A
E. It is a step-up transformer - 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 - The purpose of providing iron core in a step-up transformer is?
A. to provide coupling between primary and secondary
B. to increase the magnitude of mutual flux
C. to decrease the magnitude of mag-netizing current
D. to provide all above features - 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
