Electrical Machine - I (3140913) MCQs
MCQs of Transformers
| 121. |
Saving of copper in the auto transformer is increased as compared to two winding transformer, when transformation ratio K approaches to
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Answer:
Option (a) |
| 122. |
If W is the weight of copper in 315MVA, 400/220KV two winding transformer then what will be the weight of copper in an auto-transformer of the same rating?
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Answer:
Option (b) |
| 123. |
Three units of single-phase transformers and one single unit three-phase transformer rating
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Answer:
Option (a) |
| 124. |
As compared to ∆ − ∆ bank, the capacity of the V − V bank of transformers is ......... percent.
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Answer:
Option (a) |
| 125. |
When a V − V system is converted into a ∆ − ∆ system, an increase in capacity of the system is ......... percent.
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Answer:
Option (c) |
| 126. |
If three transformers in a ∆ − ∆ are delivering their rated load and one transformer is removed, then overload on each of the remaining transformers is ......... percent.
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Answer:
Option (c) |
| 127. |
Two transformers are connected in open delta supplies a 550 kVA balanced load at a power factor of 0.8 lagging. Calculate the kVA supply by each transformer if the load voltage is 438 volts
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Answer:
Option (b) |
| 128. |
For supplying a balanced 3 − φ load of 40-kVA, rating of each transformer in V − V bank should be nearly ......... kVA.
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Answer:
Option (b) |
| 129. |
If the load p.f. is 0.866, then the average p.f. of the V – V bank is
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Answer:
Option (b) |
| 130. |
Out of the following given choices for polyphase transformer connections which one will you select for three-to-two phase conversion?
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Answer:
Option (a) |
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