Question

Biot - savarts law
$d{B}^{\to }=\frac{\mu o}{4\pi }$ $\frac{id{l}^{\to }\times r^{\to }}{|r{|}^3}$

Answer 1

The Biot-Savart Law states that the magnetic intensity at any point due to a steady current in an infinitely long straight wire is directly proportional to the current and inversely proportional to the distance from point to wire, and relates magnetic fields to the currents which are their sources. Finding the magnetic field resulting from a current distribution involves the vector product, and is inherently a calculus problem when the distance from the current to the field point is continuously changing.