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A circular coil of N turns and radius R carries current I. Its magnetic dipole moment is
AπIR²
BNIR
CNIπR²
DN²IπR
Answer & Solution
Correct answer: C. NIπR²
1. Magnetic moment for a single loop is m = IA, where A is the loop area.
2. For a circular loop of radius R, A = πR².
3. With N turns, the moment scales linearly: m = NIA.
4. Combining: m = NIπR².
_Source: NCERT Class 12 Physics Ch 4 "Moving Charges and Magnetism", §4.10.2_
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