Orsted found that the needle of a compass could be redirected if placed near a wire carrying current. This illustrated a fundamental physics finding that

Orsted found that the needle of a compass could be redirected if placed near a wire carrying current. This illustrated a fundamental physics finding that a magnetic field exerts a force on a charge.

Explanation:

In the Orsted's experiment he placed a magnetized needle next to a conductor through which an electric current was circulating. Incredibly, the needle deviated, evidencing the presence of a magnetic field. The conclusion was that electric currents generate magnetic fields, thus demonstrating the relationship between electric currents and magnetic fields, , which can exert a force on a charge.