The Hall Effect may be used to 

1. Determine whether the semiconductor is p-type or n - type.

2. Determine the carrier concentration.

3. Calculate the mobilty.

Which of the above statements are correct?

Hall Effect:

It states that if a specimen (metal or semiconductor) carrying a current (I) is placed in a transverse magnetic field (B), an electric field is induced in the direction perpendicular to both I and B.

Hall Voltage is given by:

The hall coefficient is given as:

Where,

ρ = charge density = σ / μ 

n = charge concentration

σ = conductivity

μ = mobility constant

Hence Hall coefficient becomes

• The Hall effect provides information on the sign, concentration, and mobility of charge carriers in the normal state.
• A positive sign for the Hall coefficient indicates that the majority carriers are holes and semiconductor is P-type.
• A negative sign for the Hall coefficient indicates that the majority carriers are electrons and semiconductor is N-type.

Applications of Hall-effect: 

Hall effect can be used to find:

1. Carrier concentration

2. Type of semiconductor

3. Conductivity

4. Mobility

It cannot be used to find a magnetic field.

Common Confusion Point:

Looking at the formula one can think that the magnetic field can be calculated but in HALL Experiment, perpendicular MAGNETIC field and electric field are applied on the material and other parameters are measured.