<P> Three discoveries challenged this foundation of magnetism , though . First , in 1819 , Hans Christian Ørsted discovered that an electric current generates a magnetic field encircling it . Then in 1820 , André - Marie Ampère showed that parallel wires having currents in the same direction attract one another . Finally , Jean - Baptiste Biot and Félix Savart discovered the Biot -- Savart law in 1820 , which correctly predicts the magnetic field around any current - carrying wire . </P>
<P> Three discoveries challenged this foundation of magnetism , though . First , in 1819 , Hans Christian Ørsted discovered that an electric current generates a magnetic field encircling it . Then in 1820 , André - Marie Ampère showed that parallel wires having currents in the same direction attract one another . Finally , Jean - Baptiste Biot and Félix Savart discovered the Biot -- Savart law in 1820 , which correctly predicts the magnetic field around any current - carrying wire . </P>
who discovered the magnetic field of electric current
who discovered the magnetic field of electric current
Hans Christian Ørsted
Hans Christian Ørsted