For power transformer of larger ratings, the tapping’s are located in the middle portion of the winding to

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ESE Electrical 2013 Paper 2: Official Paper

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Answer 1

Generally, for power transformers of larger ratings, the tappings are located in the middle portion of the winding to reduce the magnetic asymmetry.
If the tappings are provided at the end of the windings there is a possibility of axial forces in addition to radial which makes, the windings mechanically unstable.
The radial force which is bursting in nature and acts outwards does not compress the two windings since they carry currents in opposite directions.
Unbalanced axial force can cause dislocation of winding along the core limb especially during inrush and short circuit conditions because of large mmf to unbalance.
To reduce the mechanical force affecting the winding during short-circuits tappings are provided in the middle of the winding.