64. Scott connections are used for
A. single-phase to three-phase transformation
B. three-phase to single-phase transformation
C. three-phase to three-phase & two-phase transformations
D. any of the above
65. In Scott connections, the neutral point divides the teaser winding in the ratio
A.13
B.12
C.11
D.14
66. The secondary line voltage is maximum for which of the following connection?
A. delta-delta
B. star-star
C. delta-star
D. star-delta
67. Three units of 15 transformers are connected in A?V to supply a 3-phase load from a 400 V. 3. source. The line voltage on the load side is
A. 1000 V
B. 80 V
C. 3464 V
D. 803 V
68. The secondary of a PT is generally designed for
A. 220 V
B. 110 V
C. 150V
D. 11 V
69. The secondary of a CT is generally designed for
A. 100 A
B. 10 A
C. 5 A
D. 0.5 A
70. The maximum efficiency of a 100 kVA transformer having iron loss of 900 kW and F.L. Cu loss of 1600 W occurs at
A. 56.3 kVA
B. 133.3 kVA
C. 75 kVA
D. 177.7 kVA
Page 10 of 45