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प्रश्न
The adjacent diagram shows a coil would around a soft iron bar XY. (a) State the polarity at the end X and Y as the switch is pressed. (b) Suggest one way increasing the strength of electromagnet so formed.
उत्तर
(a)X-north pole, Y –south pole. (b)By reducing resistance of circuit by mean of rheostat to increase current.
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