A magnetic field is the magnetic effect of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude (or strength); as such it is a vector field.
The Biot–Savart law is an equation describing the magnetic field generated by an electric current. It relates the magnetic field to the magnitude, direction, length, and proximity of the electric current. The law is valid in the magnetostatic approximation and is consistent with both Ampère’s circuital law and Gauss’s law of magnetism. It is named after Jean-Baptiste Biot and Félix Savart who discovered this relationship in 1820.
|Forces on moving charges in magnetic fields|
|Forces on current-carrying wires in magnetic fields|
|Fields of long current-carrying wires|
|Biot-Savart law and Ampere’s law|
|Test your Understanding: Chapter 4 MCQ Quiz 1 Here Take Chapter 4 ReQuiz MCQ Quiz 2 Here|
The Biot–Savart law is used for computing the resultant magnetic field B at position r generated by a steady current I (for example due to a wire): a continual flow of charges which is constant in time and the charge neither accumulates nor depletes at any point. The law is a physical example of a line integral, being evaluated over the path C in which the electric currents flow.