A circular loop of radius r is carrying current I A. The ratio of magnetic field at the centre of circular loop and at a distance r from the center of the loop on its axis is :
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A circular loop of radius r is carrying current I A. The ratio of magnetic field at the centre of circular loop and at a distance r from the center of the loop on its axis is :

G1 Physics · Accepted Answer

On the axis, B = μ₀Ir²/[2(r² + x²)³ᐟ²]. At the centre, B₁ = μ₀I/(2r). At x = r, B₂ = μ₀I/(4√2 r). Hence B₁/B₂ = 2√2.