Field of a straight wire at 10 cm

Problem

A long straight wire carries a current $I = 5$ A. Calculate the magnitude of the magnetic field at $r = 10$ cm from the wire.

Solution

For an infinite straight wire, with $\dfrac{\mu_0}{2\pi} = 2\cdot 10^{-7}$:

$B = \frac{\mu_0 I}{2\pi r} = \frac{2\cdot10^{-7}\cdot 5}{0{,}10} = 1{,}0\cdot10^{-5}\;\text{T}$

$\ev{B \approx 10\;\mu\text{T}}$

Links

Topics: Magnetismo Concepts: Campo magnetico