A circular coil of area 2 cm² is placed perpendicular to a magnetic field of 3 T. The coil has 10 turns and a resistance of 5 Ω. The coil is now removed from the magnetic field in 0.2 s. The charge that flows through the coil is .

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Accepted Answer

(3) 1.2 mC. Given: A = 2 cm² = 2×10⁻⁴ m²; B = 3 T normal to the coil; N = 10; R = 5 Ω; removed in 0.2 s. Idea: the induced charge is q = (N ΔΦ)/R; it depends only on the change in flux linkage, not on how quickly it happens. Initial flux linkage: NBA = 10 × 3 × 2×10⁻⁴ = 6×10⁻³ Wb; final: 0. q = (6×10⁻³)/5 = 1.2×10⁻³ C = 1.2 mC. The 0.2 s sets the average current (6 mA), but not the charge. So the charge that flows is 1.2 mC.

A circular coil of area 2 cm² is placed perpendicular to a magnetic field of 3 T. The coil has 10 turns and a resistance of 5 Ω. The coil is now removed from the magnetic field in 0.2 s. The charge that flows through the coil is ______.

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