Name: factors that affect electrical resistance
Uploaded: 2023-04-30T12:39:00.000Z
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North Carolina K-12 Science Standard Course of Study

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Physical Science

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Motion and Stability- Forces and Interactions

PS.PSc.6.2

Resistance

Cuando una corriente fluye a través de un circuito, las colisiones entre electrones y átomos en el cable causan resistencia al movimiento de los electrones, medido en ohmios.
La resistencia eléctrica de un circuito es la relación entre el voltaje aplicado y la corriente que fluye a través de él. La resistencia también depende de la resistividad del material y es equivalente a la resistividad del material multiplicada por la longitud dividida por el área de la sección transversal del alambre.
La temperatura influye en la resistencia de los materiales y se puede modelar utilizando la ecuación de resistividad.
Un componente de un circuito que reduce el flujo de corriente se conoce como resistencia, representada por dos símbolos proporcionados por el Instituto Nacional Americano de Normalización y la Comisión Electrotécnica Internacional.
El carbono es el material más común utilizado para fabricar resistencias. Las pistas de carbono están envueltas alrededor de un núcleo cerámico, que está conectado a dos cables de cobre y marcado con cuatro bandas para identificar la resistencia.
Las dos primeras bandas de colores representan los dos primeros dígitos de la resistencia, mientras que el tercer y cuarto color representan su multiplicador y tolerancia.

<ol>
	<li>OpenStax. (2019). Física Universitaria Vol. 2. [Versión web], págs. 396-398. Obtenido de <a href="https://openstax.org/books/university-physics-volume-2/pages/9-3-resistivity-and-resistance">https://openstax.org/books/university-physics-volume-2/pages/9-3-resistivity-and-resistance</a></li>
</ol>

resistencia

Cuando una corriente se mueve a través de cualquier conductor, el conductor provoca cierto nivel de dificultad para que la corriente fluya. La medida de esa dificultad se conoce como la resistencia del material y se representa por R. Cada material tiene su propia resistencia. En el caso de los conductores, se emite calor cuando una corriente pasa a través de ellos. La resistencia depende de la resistividad del material. La resistividad es una característica del material utilizado para fabricar componentes eléctricos, mientras que la resistencia es una característica del propio componente. Para calcular la resistencia, considera una sección de alambre conductor con un área de sección transversal A, una longitud L y una resistividad ρ. Una batería se conecta a través del conductor, proporcionando una diferencia de potencial ΔV a través de él. La diferencia de potencial produce un campo eléctrico que es proporcional a la densidad de la corriente: <img alt="Equation1" src="/files/ftp_upload/13747/13747_Equation_1.svg" style="text-align: center; height: 13px;"> La magnitud del campo eléctrico a través de un segmento del conductor es igual al voltaje dividido por la longitud, y la magnitud de la densidad de corriente es igual a la corriente dividida por el área de sección transversal. Al sustituir los valores y recordar que el campo eléctrico es proporcional a la resistividad y la densidad de corriente, se puede establecer una relación entre el voltaje y la corriente: <img alt="Equation2" src="/files/ftp_upload/13747/13747_Equation_2.svg" style="text-align: center; height: 26px;"> La resistencia de un material se puede definir como la razón entre el voltaje y la corriente que pasa a través de él y se representa en ohmio. La resistencia de un segmento cilíndrico de un conductor es igual a la resistividad del material multiplicada por la longitud dividida por el área: <img alt="Equation3" src="/files/ftp_upload/13747/13747_Equation_3.svg" style="text-align: center; height: 26px;"> La resistencia de un objeto también depende de la temperatura. Para un cilindro dado, si la longitud y el área no cambian mucho con la temperatura, la resistencia del material tiene la misma dependencia de temperatura que la resistividad: <img alt="Equation4" src="/files/ftp_upload/13747/13747_Equation_4.svg" style="text-align: center; height: 13px;">

Donde R₀ es la resistencia original a temperatura ambiente, R es la resistencia después de un cambio de temperatura, y α es el coeficiente de temperatura del material.

Resistencia

Cuando una corriente se mueve a través de cualquier conductor, el conductor causa cierto nivel de dificultad para que la corriente fluya. La medida de esa dificultad es conocida...

Education

Educación

JoVE Core

Physics

Física

Unit 1

Unidad 1

Current and Resistance

Corriente y resistencia

KEY TERMS AND CONCEPTS

TÉRMINOS Y CONCEPTOS CLAVE

factors that affect electrical resistance

Electrical resistance describes how much a conductor opposes the flow of current. It is represented by R. When current passes through a conductor, heat is also produced. Resistance is tied to the material’s resistivity, which is a property of the material used to make an electrical component.

Resistance is different from resistivity. Resistivity belongs to the material itself, while resistance belongs to the finished component. To study this relationship, consider a wire with length L, cross-sectional area A, and resistivity ρ. If a battery provides a potential difference ΔV across the wire, the voltage creates an electric field in the conductor.

The electric field across the wire segment equals the voltage divided by the length. The current density equals the current divided by the cross-sectional area. Because the electric field is proportional to resistivity and current density, these values can be combined to relate voltage and current. Resistance is then defined as the ratio of voltage to current and is measured in ohms.

For a cylindrical conductor, resistance equals resistivity multiplied by length divided by area. Resistance also changes with temperature. If the length and area stay nearly the same as temperature changes, the resistance follows the same temperature dependence as the resistivity. In that case, R0 is the original resistance at room temperature, R is the resistance after the temperature change, and α is the temperature coefficient of the material.

Factors That Affect Electrical Resistance

factors-that-affect-electrical-resistance

electrical current

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resistance

Electrical resistance describes how much a conductor opposes the flow of current. It is represented by R. When current passes through a conductor, heat is also produced. Resistance is tied to the material’s resistivity, which is a property of the material used to make an electrical component. Resistance is different from resistivity. Resistivity belongs to the material itself, while resistance belongs to the finished component. To study this relationship, consider a wire with length L,...

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key terms and concepts

Learn how resistance depends on resistivity, wire length, cross-sectional area, voltage, current, and temperature in conductors and electrical circuits.

Factors That Affect Electrical Resistance | JoVE K12

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Factors That Affect Electrical Resistance

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