Physicist — Edwin Herbert Hall (Gorham, 1855 – Cambridge, 1938) was an American physicist, professor at Harvard University. In 1879, while still a doctoral student at Johns Hopkins University, he discovered the phenomenon that bears his name: when a current-carrying conductor is placed in a perpendicular magnetic field, a transverse potential difference appears across its sides, known as the Hall voltage. This effect directly demonstrated that moving charges in a conductor experience the Lorentz force, and made it possible to determine the sign and density of the charge carriers. The Hall effect still underlies magnetic-field and current sensors widely used in technology today, and its quantum version, discovered a century later, has been awarded several Nobel Prizes. Hall also devoted much of his career to teaching and physics education.

Theories and contributions

  • Hall effect — In a conductor carrying current in a transverse magnetic field, a transverse voltage appears: VH=IBnqdV_H=\dfrac{I\,B}{n\,q\,d}, which reveals the sign and density of the charge carriers.

Linked atoms

1 linked atom.

17 Il campo magnetico