Which scientist discovered the Hall effect in 1879?

Edwin Hall discovered the Hall effect in 1879.

While working at Johns Hopkins University, Hall found that a magnetic field deflects moving charge carriers in a current-carrying conductor, creating a voltage across the conductor. This transverse voltage is called the Hall voltage.

The effect provided evidence about the behavior of electric charge in materials and later became useful for identifying whether charge carriers are positive or negative. Hall sensors now detect magnetic fields, measure position and speed, and help control brushless motors.

The Hall effect is not the same as electromagnetic induction in a changing magnetic field. It occurs because a magnetic field pushes moving charge carriers sideways, causing charge separation across the material.