Hello,

In Simple words, 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.

The application of  Biot-Savart Law include the following

• This law can be used for calculating magnetic reactions even on the level of molecular or atomic.
• It can be used in the theory of aerodynamic for determining the velocity encouraged with vortex lines.

Hope this was helpful