Question

In 1820, Hans Christian Oersted noticed that a compass needle deflected near a current-carrying wire. What did this observation prove for the first time?

Options

• Magnetic fields produce electric currents

• Current-carrying wires produce electric charges

• Electric currents produce magnetic fields

• Compass needles are deflected by electric fields

Answer 1

Oersted's observation of a deflecting compass needle near a current-carrying wire proved for the first time that electric currents produce magnetic fields. This established the connection between electricity and magnetism and motivated further quantitative study.