An element Δℓ = Δx î is placed at the origin and carries a large current I = 10 A. The magnetic field on the y-axis at a distance of 0.5 m from the element Δx of 1 cm length is :

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G1 Physics · Accepted Answer

Image Biot-Savart law for a small current element: dB = (μ₀/4π) I(dℓ × r̂)/r² Here: I = 10 A Δℓ = 1 cm = 10⁻² m r = 0.5 m The current element is along +î and the field point is on +y-axis, so: î × ĵ = k̂ Magnitude: B = 10⁻⁷ × [10 × 10⁻²]/(0.5)² = 4 × 10⁻⁸ T Direction is +k̂.