43. The power factor in a transformer
A. is always unit
B. is always leading
C. is always lagging
D. depends on the power factor of load
44. Which of the following transformers will be largest is size?
A. 1 kVA, 50 Hz
B. 1 kVA, 60 Hz
C. 1 kVA, 100 Hz
D. 1 kVA, 500 Hz
45. In a three-phase transformer, the phasedifference between the primary voltage and the induced secondary winding voltage is
A. 90?
B. 120?
C. 180?
D. 270?
46. When the secondary of a transformer is loaded, the current in the primary side will
A. not be effected
B. increase
C. decrease
D. be the sum of no-load current and excess current drawn due to the secondary current
47. In an ideal transformer on no-load, the primary applied voltage is balanced by
A. the secondary voltage
B. drop across resistances and reactances
C. secondary induced emf
D. primary induced emf
48. Use of higher flux density in transformer design
A. increases the weight per kVA decreases the weight per kVA
B. increases the weight per kW
C. decreases the weight per kW
D.
49. The leakage flux of a transformer is defined as
A. the flux which is linked with both the primary and the secondary windings
B. the flux which is linked either only with the primary or only with the secondary
C. the flux whose path is exclusively through the air
D. none of these
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