Quoc: Three discoveries challenged this foundation of magnetism, though. First, in 1819, Hans Christian rsted discovered that an electric current generates a magnetic field encircling it. Then in 1820, Andre-Marie Ampere showed that parallel wires having currents in the same direction attract one another. Finally, Jean-Baptiste Biot and Felix Savart discovered the Biot -- Savart law in 1820, which correctly predicts the magnetic field around any current-carrying wire.

Answer this question based on the passage: who discovered the magnetic field of electric current?
HW Chung: OK, some thoughts:
The important part for answering this question is: First, in 1819, Hans Christian rsted discovered that an electric current generates a magnetic field encircling it. The answer is Hans Christian rsted.