Biot-Savart Law

(noun)

An equation that describes 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 for magnetism.

Related Terms

Examples of Biot-Savart Law in the following topics:

  • Ampere's Law: Magnetic Field Due to a Long Straight Wire

    • Current running through a wire will produce a magnetic field that can be calculated using the Biot-Savart Law.
    • For a closed curve of length C, magnetic field (B) is related to current (IC) as in Ampere's Law, stated mathematically as:
    • This can be related to the Biot-Savart law.
    • For a short, straight length of conductor (typically a wire) this law generally calculates partial magnetic field (dB) as a function of current for an infinitesimally small segment of wire (dl) at a point r distance away from the conductor:

  • Electric Currents and Magnetic Fields

    • The formal statement of the direction and magnitude of the field due to each segment is called the Biot-Savart law.
    • The Biot-Savart law is written in its complete form as:
    • The reader may apply the simplifications in calculating the magnetic field from an infinite straight wire as above and see that the Biot-Savart law reduces to the first, simpler equation.
    • A more fundamental law than the Biot-Savart law is Ampere's Law, which relates magnetic field and current in a general way.
    • Ampere's Law is also a component of Maxwell's Equations.