A very long thin wire produces a magnetic field of $0.0020 \times 10 ^ { - 4 } \mathrm {~T}$ at a distance of $1.0 \mathrm {~mm}$ from the wire. What is the magnitude of the current? (?₀ = 4? × 10^-7 T ? m/A)

Question

Quizplus · Accepted Answer

The magnitude of the current can be calculated using the formula for the magnetic field of a long, thin wire:$$B = \frac{\mu_0 I}{2\pi r}$$where:* B is the magnetic field strength* μ0 is the permeability of free space (4π × 10^-7 T ? m/A)* I is the current* r is the distance from the wirePlugging in the given values, we get:$$0.0020 	imes 10 ^ { - 4 } \mathrm {~T} = \frac{4\pi 	imes 10^{-7} \mathrm {~T~m/A} 	imes I}{2\pi 	imes 0.001 \mathrm {~m}}$$Solving for I, we get:$$I = 1.0 \mathrm {~mA}$$

A Very Long Thin Wire Produces a Magnetic Field Of 0.0020