In Oersted's Experiment, a compass needle deflects when placed parallel to a current-carrying wire due to the magnetic field generated by the current. When the needle is positioned perpendicularly, it aligns with the magnetic field, resulting in no observable deflection. This occurs because the needle is already oriented in the direction of the magnetic force and cannot change its position further. The magnetic effect of the current is only evident when the needle is free to move into alignment with the field. Understanding this principle is crucial for grasping the fundamentals of electromagnetism.
