This law was named after Jean Baptist Biot and Felix Savart in 1820. The Biot Savart law is an equation that illustrates the magnetic field made by a current carrying wire, permitting the calculation of its strength at various points. They obtained the mathematical expression for the magnetic flux density.
This is because when a compass is placed near an electric wire, the compass needle tends to change direction. The law is valid in magnetostatic approximation. It is an equation describing the magnetic field generated by a constant electric current.