Hall effect is an electrical phenomenon that occurs when a current flows through a material in a magnetic field. For example, if a material has a current flowing through it perpendicular to a magnetic field passing through the material, the Hall effect is observed as a voltage across the material. The Hall voltage is perpendicular to both the direction of the current and the direction of the magnetic field.
For any given material, the Hall voltage is proportional to the current and the magnetic field. Different materials produce different Hall voltages. Thus, scientists can use the Hall effect to describe the electrical properties of materials and to measure the magnetic fields or currents. For example, the Hall voltage produced in metals is much smaller than that produced in semiconductor materials. The Hall effect was discovered in 1879 by the American physicist Edwin H. Hall.
