Question

An element dl=dx icap is placed at the origin and carries a large current I =10A .What is the magnetic field on the y-axis at a distance of 0.5m .dx =1cm?

Answer 1

dℓ = dx = 10^–2 m

I = 10A

r = 0.5 m

dB^➙ = (μ₀ / 4π)[(I dℓ^➙ × r^➙) / r³] = [(μ₀ I dℓ sinθ) / (4π × r²)]

∴ magnetic field on y axis = [(4π × 10^–7) / 4π] × [(10 × 10^–2) / (0.5)²]

= [(10)^–8 / (25 ×10^–2)] = 0.04 × 10^–6

= 4 × 10^–8 T

i.e. dB^➙ = 4 × 10⁸ k˄ T (y axis)