A single-phase autotransformer has a total of 1000 turns in its winding. If the secondary connection is tapped at 400 turns, determine the transformation ratio (k).
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Answer & Explanation
Correct AnswerA. 0.4
Quick Explanation
For the step-down connection described, the transformation ratio is the tapped secondary turns divided by total primary turns. Thus k = N2/N1 = 400/1000 = 0.4.
Formula / Key Relation
k = V₂/V₁ = N₂/N₁ = 400/1000 = 0.4
Detailed Explanation
Correct Answer
A — 0.4
Explanation
For the step-down connection described, the transformation ratio is the tapped secondary turns divided by total primary turns. Thus k = N2/N1 = 400/1000 = 0.4.
Key Concept
Transformation Ratio
Formula
k = V₂/V₁ = N₂/N₁ = 400/1000 = 0.4
Exam Point
Autotransformer ratio still follows turns ratio.
Quick Trick
Autotransformer ratio still follows turns ratio.
Exam Tip
Autotransformer ratio still follows turns ratio.
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