# Hall effect

When a transverse magnetic field ‘B’is applied to a specimen (of metal (or) Semi conductor) carrying a current Ian Electric field E is induced perpendicular to both I and B. This phenomenon is known as Hall effect. The figure shows the  experimental arrangement to observe Hall effect  Now

I Current flowing in the semi conductor (x-direction)

B Applied Magnetic field (z-direction)

E Induced Electric field is along y-direction perpendicular to both I and B.

Now charge carrier electron is moving under the influence of two fields both electric field(E) and Magnetic field(B).

i.e, electron is under the influence of both E and B, E applies some force on electron similarly B.

under equilibrium

, where is the drift velocity

Electric field Intensity due to Hall effect is

is the Hall voltage between plates 1 and 2.

and d- is the distance between the two plates.

In an N-type Semi conductor, the current is due to electrons , plate 1 is negatively charged compared to plate 2.

The current density J related to charge density is

W- width of the specimen, d- height of the specimen.

From EQN(I) and From EQN(II)

up on multiplying with ‘d’ on both sides

from EQN(III)

, let Hall coefficient

.

Uses of Hall effect (or) Applications of Hall effect:-

• Hall effect specifies the type of semi conductor that is P-type (or) N-type.when is positive it’s a P-type semi conductor and    negative means  it’s  N-type semi conductor.
• It is used to find out carrier concentrations ‘n’ and ‘p’ , by using either   or .
• To find out mobilities and using the equation .
• Some other applications of Hall effect are measurement of velocity, sorting,limit sensing etc.
• used to measure a.c power and the strength of Magnetic field and also finds the angular position of static magnetic fields in a magnetic field meter.
• used in Hall effect multiplier, which gives the output proportional to product of two input signals.     (No Ratings Yet) Loading...