211. For transformers upto a capacity of kVA air blast cooling is provided.
A.2500
B.5000
C.10000
D.20000

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212.  As the supply frequency of a transformer increases its rating
A. increases
B. decreases
C. remains unchanged
D. none of the above

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213.  Which of the following methods in used for cooling of transformers upto a capacity of 10 MVA?
A. Air blast cooling
B. Forced oil cooling
C. Oil natural cooling
D. None of the above

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214. The nominal short-circuit voltage of the transformer is defined as percentage of
A. the rated primary voltage
B. the rated secondary voltage
C. the test voltage
D. none of the above

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215. In a transformer frictional loss is
A. 5% of total loss
B. 10% of total loss
C. 20% of total loss
D. zero

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216.  A distribution transformer has low flux density because
A. it is constantly connected to the supply
B. it is required to give better power factor
C. it is normally a small transformer
D. iron is quite cheap

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217. Spiral core transformer which has core made up of steel strip has the following advantage.
A. Less weight
B. Lighter construction
C. Minimum losses
D. All above

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