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Question
The primary windings of a step-up transformer are usually made of thicker wire than the secondary. Explain.
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Solution
In case of a step-up transformer, the e.m.f. across the secondary coil is greater than across the primary coil. So the current in the secondary coil is less than in the primary coil. Therefore to reduce heat loss in the windings, the primary coil is made of thicker wire than the secondary coil.
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