Hall Effect and Hall Voltage Fundamentals

Hall Effect

• The Hall Effect was discovered by Edwin Herbert Hall in 1879.
• When a current-carrying conductor or semiconductor is exposed to a perpendicular magnetic field, a voltage develops at a right angle to the current path.
• This voltage is referred to as Hall voltage.

Hall Voltage Generation

• Charge carriers in a conductive plate move linearly from one end to the other when a current flows.
• These charge carriers generate magnetic fields.
• When a magnet is placed near the plate, the magnetic field of the charge carriers is distorted.
• This distortion alters the straight flow of charge carriers.
• The force that disrupts the direction of charge carrier flow is called the Lorentz force.
• Due to the magnetic field distortion, negatively charged electrons are deflected to one side of the plate, while positively charged holes are deflected to the other.
• This separation of charges creates a potential difference, called the Hall Voltage, which can be measured using a meter.

Hall Coefficient (RH)

• Mathematical expression: RH = E/(JB), where J is current density, E is the induced electric field, and B is magnetic field strength.
• Hall Voltage (VH) formula: VH = (IB)/(qnd) where I is current, B is magnetic field strength, q is charge, n is charge carrier density, and d is the thickness of the sensor.
• The Hall coefficient is positive when the number of positive charges exceeds the number of negative charges.
• It's negative when the number of electrons is greater than the number of holes.

Applications of the Hall Effect

• Determining if a semiconductor is N-type or P-type.
• Measuring carrier concentration in semiconductors.
• In magnetic field sensing equipment.
• In proximity detectors.
• In Hall effect sensors and probes.

Magnetic Materials - Terms

• Magnetic Susceptibility (χ): The ratio of magnetization intensity in a sample to the magnetic field intensity that produces it. It has no units and is represented as χ = M/H.
• Magnetization: The process of converting a non-magnetic material into a magnetic material.
• Intensity of Magnetization: The magnetic moment per unit volume.
• Relative Permeability: The ratio of flux density produced in a material to the flux density produced in a vacuum by the same magnetizing force.

Magnetic Field Quantities

• Magnetic Flux (Φ): The total number of magnetic lines of force in a magnetic field. Its unit is the Weber.
• Magnetic Flux Density (B): Magnetic flux per unit area perpendicular to the direction of flux. Its unit is Wb/m2.
• Magnetic Field Intensity (H): Magneto motive force per unit length of the magnetic circuit. Also called magnetic field strength or magnetizing force. Its unit is A-turns/m.
• Permeability (µ): The ability of a material to conduct magnetic flux through it. Its unit is H/m.

Magnetic Dipole Moment

• A vector quantity that measures the strength and orientation of a magnet or object that creates a magnetic field.
• It's also a measure of the strength of a small current loop that acts like a tiny magnet.
• The magnetic dipole moment of an object determines the torque it experiences in a given magnetic field.
• A stronger magnetic moment results in a stronger magnetic field and greater torque.

This quiz explores the Hall Effect, discovered by Edwin Herbert Hall in 1879, and its impact on charge carriers in a conductive plate. It covers how magnetic fields and Lorentz force influence the behavior of electrons and holes, leading to the generation of Hall voltage. Test your knowledge on this fascinating physical phenomenon!