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Question
A circular coil of 250 turns and diameter 18 cm carries a current of 12A. What is the magnitude of magnetic moment associated with the coil?
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Solution
M = N I A where A =π r2
∴ M = NI π r2
∴ M = 250 x 12 x 3.14 x 81 x10-4
∴ M = 76.30 A-m2
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