In pheesics, particularly electromagnetism, the Biot–Savart law (Lua error in package.lua at line 80: module 'Module:IPAc-en/data' not found. or Lua error in package.lua at line 80: module 'Module:IPAc-en/data' not found.) is an equation describin the magnetic field generatit bi an electric current. It relates the magnetic field tae the magnitude, direction, length, an proximity o the electric current. The law is valid in the magnetostatic approximation, an is consistent wi baith Ampère's circuital law an Gauss's law for magnetism. It is named for Jean-Baptiste Biot an Félix Savart who discovered this relationship in 1820.