# Biot-Savart Law¶

The Biot-Savart Law derives the magnetic field B due to a current:

Here, is the magnetic constant, is the infinitesimal length and direction of a section of infinitesimally thin wire current we are integrating over, I is the amount of current in that section, and r is the displacement vector from the section of wire current to the point where B is measured. may also be replaced with if a current density J occupies a volume element dV.

## SIMION Specific¶

SIMION 8.0.3 can compute magnetic fields from wire currents using the Biot-Savart law using the simionx.MField - Biot-Savart magetic field calculations library. In SIMION 8.1.0.19, these wires can also be drawn on the SIMION View screen. Examples of this include