Hall Effect

E and B  Charged particles can be subject to both electric and magnetic fields.

Deflected Current  A wire with current has moving charges. Current due to electric field Subject to a force from magnetism.  The force can be related to the current. Charge times velocity Current time length q B FMFM l

Charge Pileup  Moving current in the magnetic field will move carriers. Only carriers of current move Motion same for either sign charge.  The charges set up an electric field. Opposes magnetic force  This is called the Hall effect. q B FMFM l qq FEFE A

Cross Potential  An electric field is created in the conductor. Perpendicular to current and magnetic field  The electric field creates a potential V. Based on width w Area is width times thickness x q B E w qq Al I

Carrier Sign  The Hall voltage depends on the magnetic field, current and the charge carrier properties. Number density n Charge q  The sign of the potential matches the sign of the charge carriers. Negative for electrons  Some conductors have positive carriers. q B E w qq Al I

Hall Probe  The Hall effect can be used to measure magnetic fields. Apply known current to known materialApply known current to known material Measure Hall voltageMeasure Hall voltage Integrity Design, Inc.

Blood Flow  Similar to the Hall effect, the velocity of blood can be measured by its ions. next