Question

In a physics lab a student discovers that the magnitude of the magnetic field in a specific location near a long wire is 21.919 microTesla. If the wire carries a current of 35.483 A, what is the distance from the wire to that location ?

Answer 1

We will have the following:

First, we have that the permeability of free space is:

`\mu_0=4\pi\ast10^(-7)Tm/A`

Then:

`\begin{gathered} B=(\mu_0I)/(2r\pi)\Rightarrow r=(\mu_0I)/(2B\pi) \\ \\ \Rightarrow r=((4\pi\ast10^(-7)Tm/A)(35.483A))/(2\pi(2.1919\ast10^(-5)T))\Rightarrow r=0.3237647703...m \\ \\ \Rightarrow r\approx0.32m \end{gathered}`

So, the distance is approximately 0.32 m.