Describe classic experiments illustrating magnetic interaction.

The action of the magnetic field of the conductor with current on the magnetic needle. Hans Christian Oersted placed a straight metal conductor above the magnetic needle, parallel to the arrow. When an electric current was passed through the conductor, the arrow was turned almost perpendicular to the conductor. When the direction of the current was changed, the arrow turned 180 °. A similar reversal was observed if the wire was moved to the other side, not above, but below the arrow.
The action of the Ampere force can be shown by passing a large current through two tape conductors – foil strips, or passing a relatively small current through two freely hanging coils with a sufficiently large number of turns. These experiments demonstrate the attraction of parallel currents and the repulsion of antiparallel currents.