When this co-efficient is multiplied by the current density and the magnetic flux density, the result is the strength of the electric field produced within a conductor subjected to a strong transverse magnetic field.  
The coefficient named after him is 1 over the quantity n times e, where e is the electronic charge and n is the number of charge carriers per unit volume.  When this co-efficient is multiplied by the current density and the magnetic flux density, the result is the strength of the electric field produced within a conductor subjected to a strong transverse magnetic field.  FTP, identify the scientist after whom this effect is named, in which the potential difference develops at right angles to both the current and the field.
The coefficient named after him is 1 over the quantity n times e, where e is the electronic charge and n is the number of charge carriers per unit volume.  
Edwin Hall (accept the Hall effect)