How do electric circuits interfere with magnetic compasses?

Electric circuits interfere with magnetic compasses by generating their own magnetic fields, which can deflect the compass needle from its alignment with the Earth's magnetic field. This deflection, known as deviation, occurs because any current flowing through a circuit produces a magnetic field that interacts with the magnetized needle.123

In contrast, a gyrocompass is immune to such magnetic interferences, including those caused by electric circuits, steel structures, or ore deposits. Because the gyrocompass relies on the properties of a continuously driven gyroscope, gravity, and the rotation of the Earth to seek true north, it remains unaffected by the local magnetic influences that disrupt traditional magnetic compasses.45