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Hall effect
Generation of electromotive force across a conductor or semiconductor when it is carrying a current perpendicular to a magnetic field around it. The voltage is at 90° to both the direction of the current and the direction of the magnetic field. The effect was discovered in 1879 by the American physicist Edwin H. Hall (1855-1938).
If a current (I) is passed through a conducting crystal in a direction perpendicular to that of an applied magnetic field (H), the conductor develops a potential (V) between the faces wchih are mutually perpendicular to both the direction of current and the magnetic field. The magnitude of the potential difference is given by
where N is the number of current carriers, e is the electronic charge, and d is the distance of separation of the two faces across which the potential is developed.
The Hall effect can be used to test the electrical properties of materials and in ascertaining the strength of magnetic fields. It is also the basis of the Hall effect thruster.
Related categories
• ELECTRICITY AND MAGNETISM
• SOLID STATE PHYSICS
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