A. nearly full load
B. 70% full load
C. 50% full load
D. no load
Related Mcqs:
- Power transformers are generally designed to have maximum efficiency around__________?
A. no-load
B. half-load
C. near full-load
D. 10% overload - Distribution transformers are generally designed for maximum efficiency around________________?
A. 90% load
B. zero load
C. 25% load
D. 50% load - Two transformers are connected in parallel. These transformers do not have equal percentage impedance. This is likely to result in____________?
A. short-circuiting of the secondaries
B. power factor of one of the transformers is leading while that of the other lagging
C. transformers having higher copper losses will have negligible core losses
D. loading of the transformers not in proportion to their kVA ratings - The efficiency of two identical transformers under load conditions can be determined by_______________?
A. short-circuit test
B. back-to-back test
C. open circuit test
D. any of the above - The efficiencies of transformers compared with that of electric motors of the same power are____________?
A. about the same
B. much smaller
C. much higher
D. somewhat smaller
E. none of the above - If the percentage impedances of the two transformers working in parallel are different, then______________________?
A. transformers will be overheated
B. power factors of both the transformers will be same
C. parallel operation will be not possible
D. parallel operation will still be possible, but the power factors at which the two transformers operate will be different from the power factor of the common load - Short circuit test on transformers is conducted to determine____________?
A. hysteresis losses
B. copper losses
C. core losses
D. eddy current losses - For the parallel operation of single phase transformers it is necessary that they should have___________?
A. same efficiency
B. same polarity
C. same kVA rating
D. same number of turns on the secondary side. - Which of the following protection is normally not provided on small distribution transformers ?
A. Overfluxing protection
B. Buchholz relay
C. Overcurrent protection
D. All of the above - Losses which occur in rotating electric machines and do not occur in transformers are___________?
A. friction and windage losses
B. magnetic losses
C. hysteresis and eddy current losses
D. copper losses
