Arago's rotations is an observable magnetic phenomenon and effect discovered by François Arago in 1824.A magnetic needle is freely suspended on a pivot or string, a short distance above above a copper disc. If the disk is stationary, the needle aligns itself with the Earth's magnetic field. If the disc is rotated in its own plane, the needle rotates in the same direction as the disc. (The effect decreases as the distance between the magnet and the disk increases.)Variations:If the needle is not allowed to rotate, its presence retards the motion of the disc. (This might be harder to observe or measure.)If the disk is free to rotate with minimal friction, and the needle is rotated above or below it, the disk rotates in the same direction as the needle.Other non-magnetic materials having electrical conductivity (non-ferrous metals such as zinc, silver, or aluminum) will also produce the effect.Non-conductive materials (glass, wood, plastic) will not produce the effect.Relative motion of the conductor and the magnet induces eddy currents in the conductor, which produce a force or torque that tries to opposes relative motion or "couple" the objects. The same drag-like force is used in eddy current braking and magnetic damping.
Arago's rotations is an observable magnetic phenomenon and effect discovered by François Arago in 1824.A magnetic needle is freely suspended on a pivot or string, a short distance above above a copper disc. If the disk is stationary, the needle aligns itself with the Earth's magnetic field. If the disc is rotated in its own plane, the needle rotates in the same direction as the disc.

Aragon Ballroom

Arag Versicherung AG

Huesca 3–1 Zaragoza

Arag Hochhaus am Mörsenbroicher Weg