Name: hall voltage and charge carriers
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K12 Standards

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North Carolina K-12 Science Standard Course of Study

9-12

Physical Science

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Motion and Stability- Forces and Interactions

PS.PSc.6.4

The Hall Effect

Considere um condutor retangular de transporte de corrente com elétrons como portadores de carga. Quando um campo magnético é aplicado perpendicularmente ao plano do condutor, os elétrons que se movem em linha reta se desviam devido à força magnética de deflexão.
Os elétrons se acumulam em um lado do condutor, deixando cargas positivas em excesso no outro lado. Essa separação de carga cria um campo elétrico dentro do condutor, que exerce uma força elétrica em cada elétron que se opõe à força magnética.
No equilíbrio, a magnitude da força elétrica equilibra a força magnética, interrompendo a deriva dos elétrons. A diferença de potencial entre os dois lados do condutor é a tensão do salão.
Ao expressar a velocidade de deriva em termos de corrente, a tensão Hall também pode ser usada para medir a densidade numérica dos portadores de carga.
As sondas Hall medem a magnitude de um campo magnético desconhecido a partir da tensão Hall e dos parâmetros conhecidos do condutor.
Uma aplicação significativa dessa descoberta é que a polaridade da tensão Hall implica se os portadores de carga no condutor são negativos ou positivos.

<ol>
	<li>OpenStax. (2019). Física Universitária Vol. 2. [Versão Web]. Obtido de 514-516 <a href="https://openstax.org/books/university-physics-volume-2/pages/11-6-the-hall-effect">https://openstax.org/books/university-physics-volume-2/pages/11-6-the-hall-effect</a></li>
</ol>

o efeito hall

Edwin H. Hall, no ano de 1879, criou um experimento que poderia ser usado para identificar a polaridade dos portadores de carga predominantes em um material condutor. Do ponto de vista histórico, este experimento foi o primeiro a demonstrar que os portadores de carga na maioria dos metais são negativos.

<img alt="Figure1" src="/files/ftp_upload/13772/13772_Figure_1.png" style="text-align: center" />

Considere uma lâmina metálica de largura L em um campo magnético constante. Os elétrons se movem da direita para a esquerda, então a força magnética que eles experimentam empurra os elétrons para a borda superior da lâmina. Isso deixa uma carga negativa excessiva na borda superior da lâmina e uma carga positiva excessiva na borda inferior da lâmina, resultando em um campo elétrico direcionado de baixo para cima. A concentração de carga em ambas as bordas aumenta até que uma condição de equilíbrio seja estabelecida. No equilíbrio, a força elétrica nos elétrons em uma direção é equilibrada pela força magnética na direção oposta. Essa situação na qual os campos elétrico e magnético são perpendiculares entre si é chamada de situação de campo cruzado.

A corrente na lâmina I pode ser escrita em termos da velocidade de deriva vd e da área de seção transversal da lâmina A. A diferença de potencial entre as bordas da tira, também chamada de tensão de Hall, é dada por,

<img alt="Equation1" src="/files/ftp_upload/13772/13772_Equation_1.png" style="text-align: center; height: 40px;" />

A polaridade da tensão de Hall mostra se os portadores de carga são positivos ou negativos. Outra aplicação importante desse efeito é para materiais com uma densidade conhecida de portadores de carga. A tensão de Hall medida pode fornecer o valor de um campo magnético desconhecido. Em laboratórios de pesquisa nos quais os campos dos eletroímãs usados para medidas precisas devem ser altamente estáveis, uma "sonda de Hall" é comumente usada como parte do circuito eletrônico, para regular o campo.

O Efeito Hall

Edwin H. Hall, no ano de 1879, desenvolveu um experimento que poderia ser usado para identificar a polaridade dos portadores de carga predominantes em um condutor ...

Education

JoVE Core

Physics

Física

Unit 1

Unidade 1

Magnetic Forces and Fields

Forças e Campos Magnéticos

KEY TERMS AND CONCEPTS

TERMOS-CHAVE E CONCEITOS

hall voltage and charge carriers

Hall voltage and charge carriers are explained through Edwin H. Hall’s 1879 experiment. His setup helped identify the polarity of the main charge carriers in a conducting material. It also showed, for the first time, that the charge carriers in most metals are negative.

A metal slab is placed in a constant magnetic field. The electrons move from right to left, so the magnetic force pushes them toward the top edge of the slab. This leaves excess negative charge at the top and excess positive charge at the bottom. As a result, an electric field forms from the bottom edge to the top edge.

The charge buildup continues until equilibrium is reached. At that point, the electric force on the electrons balances the magnetic force in the opposite direction. This is called a crossed-field situation because the electric and magnetic fields are perpendicular to each other. The current in the slab, I, can be written in terms of the drift velocity, v d, and the cross-sectional area, A.

The potential difference between the two edges is called the Hall voltage. Its polarity reveals whether the charge carriers are positive or negative. When the density of charge carriers is known, the Hall voltage can also be used to find an unknown magnetic field. In research labs, a Hall probe is often used in electronic circuits to help regulate electromagnet fields so they stay steady for precise measurements.

Hall Voltage and Charge Carriers

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Hall voltage and charge carriers are explained through Edwin H. Hall’s 1879 experiment. His setup helped identify the polarity of the main charge carriers in a conducting material. It also showed, for the first time, that the charge carriers in most metals are negative. A metal slab is placed in a constant magnetic field. The electrons move from right to left, so the magnetic force pushes them toward the top edge of the slab. This leaves excess negative charge at the top and excess positive...

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key terms and concepts

Learn how Hall voltage forms in a magnetic field, how it reveals charge carrier polarity, and how Hall probes help measure and control magnetic fields.

Hall Voltage and Charge Carriers | JoVE K12

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Virginia  Standards of Learning

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Hall Voltage and Charge Carriers

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