= Solution
\b[The field law.] In the <Biot-Savart law>, $d\mathbf B$ is the contribution to the <magnetic flux density> at the observation point from a directed wire element $d\boldsymbol\ell$ carrying steady conventional <electric current> $I$. The vector $\mathbf R$ points from that element to the observation point, $R=|\mathbf R|$, and $\widehat{\mathbf R}=\mathbf R/R$. The constant $\mu_0$ is the <vacuum permeability>; the <cross product> sets the direction by the <right-hand rule>. Integrating the elements gives the total field, in teslas.
\b[The moment of the shown loop.] The arrows in the original PDF run counterclockwise viewed from $+z$. Thus the <magnetic dipole moment> is
$$
\boxed{\mathbf m=I\Delta x\Delta y\,\widehat{\mathbf z}.}
$$
Its units are $\mathrm{A\,m^2}$. Reversing the current reverses both this moment and the field.
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