# Biot-Savart Law

The Biotâ€“Savart law is used to find the magnetic field intensity produced by a steady current.

The Biotâ€“Savart law states that the magnetic field intensity  produced at a point P due to a differential current element Idl is

1. directly proportional to the product of current I and differential length dl,
2. directly proportional to the sine of the angle between the element and the line joining P to the element, and
3. inversely proportional to the square of the distance r.