Name: magnetic poles and everyday uses
Uploaded: 2023-04-30T12:40:25.000Z
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Physical Science

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Motion and Stability- Forces and Interactions

PS.PSc.6.4

Magnetism

El magnetismo se observó por primera vez hace más de 2500 años cerca de la antigua ciudad de Magnesia.
Los imanes se pueden encontrar en objetos cotidianos como altavoces, tarjetas de crédito, brújulas y dispositivos de memoria.
Un imán de barra tiene un polo norte y otro sur. Cuando un clavo de hierro no magnetizado se pone en contacto con él, se magnetiza.
Al igual que los polos de un imán se repelen entre sí, mientras que los polos diferentes se atraen entre sí.
Los polos de un imán no se pueden separar rompiéndolos en dos piezas. En su lugar, se obtienen imanes más pequeños, cada uno con un extremo norte y otro sur. Por lo tanto, nunca se observan monopolos magnéticos.
En una brújula de navegación, la aguja es una barra magnética delgada suspendida en su centro.
El polo norte de una brújula es atraído cerca del polo norte geográfico de la Tierra.
La Tierra también actúa como una enorme barra magnética, con su polo sur magnético cerca del polo norte geográfico y su polo norte magnético cerca del polo sur geográfico.
El eje del imán de la Tierra y el eje geográfico no coinciden. Esta desviación se denomina declinación magnética.

<ol>
	<li>OpenStax. (2019). Física Universitaria Vol. 2. [Versión web], sección 11.1, páginas 494–496. Obtenido de <a href="https://openstax.org/books/university-physics-volume-2/pages/11-1-magnetism-and-its-historical-discoveries">https://openstax.org/books/university-physics-volume-2/pages/11-1-magnetism-and-its-historical-discoveries</a></li>
</ol>

el magnetismo

Los imanes se encuentran comúnmente en objetos cotidianos, como juguetes, perchas, ascensores, timbres de puertas y dispositivos informáticos. La experimentación con estos imanes muestra que todos los imanes tienen dos polos: uno se llama norte (N) y el otro sur (S). Los polos magnéticos se repelen si son iguales y se atraen si son diferentes. Además, ambos polos de un imán atraen piezas de hierro no magnetizadas. No se puede aislar un polo magnético individual. No importa cuán pequeña sea, cada pieza de un imán contiene un polo norte y un polo sur. Esta propiedad de los imanes difiere de la propiedad de las cargas eléctricas, en las cuales tanto las cargas positivas como las negativas pueden existir de forma aislada. Un ejemplo de imán es la aguja de una brújula. Es un delgado imán en forma de barra suspendido en su centro, por lo que es libre de girar en un plano horizontal. La Tierra también actúa como un imán gigante, con su polo buscador del sur cerca de su Polo Norte geográfico. El polo norte de una brújula es atraído hacia el Polo Norte geográfico de la Tierra porque el Polo Norte geográfico de la Tierra está cerca de su polo sur magnético. En 1819, el físico danés Hans Oersted estaba realizando una demostración de conferencia para algunos estudiantes y se dio cuenta de que una brújula se movía cuando la corriente fluía en un cable cercano. Una investigación posterior sobre este fenómeno convenció a Oersted de que una corriente eléctrica de alguna manera podía causar una fuerza magnética. Hoy en día, el magnetismo desempeña muchos roles importantes en nuestras vidas. La comprensión del magnetismo por parte de los físicos ha permitido el desarrollo de tecnologías que afectan tanto a las personas como a la sociedad. Por ejemplo, la tableta electrónica en el bolso o mochila no habría sido posible sin las aplicaciones del magnetismo y la electricidad a pequeña escala. Todos los motores eléctricos contienen imanes. Los generadores, ya sea que produzcan energía hidroeléctrica o alimenten luces de bicicleta, utilizan campos magnéticos. Las instalaciones de reciclaje emplean imanes para separar el hierro de otros desechos. La investigación sobre el uso del confinamiento magnético de la fusión como fuente de energía futura ha continuado durante varios años. La resonancia magnética (MRI, por sus siglas en inglés) se ha convertido en una herramienta de diagnóstico importante en el campo de la medicina, y el uso del magnetismo para explorar la actividad cerebral es un tema de investigación y desarrollo contemporáneo. La lista de aplicaciones también incluye discos duros de computadoras, grabadoras de cinta, detección de asbestos inhalados y levitación de trenes de alta velocidad.

El magnetismo

Los imanes se encuentran comúnmente en objetos cotidianos, como juguetes, perchas, ascensores, timbres y dispositivos informáticos. La experimentación con estos imanes muestra ...

Education

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Unit 1

Unidad 1

Magnetic Forces and Fields

Fuerzas y campos magnéticos

KEY TERMS AND CONCEPTS

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magnetic poles and everyday uses

Magnetism appears in many everyday objects, from toys and hangers to elevators, doorbells, and computer devices. Magnets have two poles, called north and south. Like poles repel each other, while unlike poles attract. Both poles can also attract unmagnetized iron. A single magnetic pole cannot be isolated, because every part of a magnet contains both a north pole and a south pole.

A compass needle is a simple example of a magnet. It is a thin bar magnet suspended at its center, so it can turn freely in a horizontal plane. Earth also behaves like a giant magnet. Its south-seeking pole is near the geographic North Pole. That is why the north end of a compass points toward Earth’s geographic North Pole, which is close to Earth’s magnetic south pole.

The link between electricity and magnetism became clear in 1819. During a lecture demonstration, Danish physicist Hans Oersted noticed that a compass needle moved when current flowed in a nearby wire. Further study showed that an electric current can create a magnetic force. This discovery helped scientists connect electric currents with magnetic effects.

Magnetism is important in many modern technologies. Electric motors contain magnets, and generators use magnetic fields to produce power, including hydroelectric power and bicycle lights. Recycling facilities use magnets to separate iron from other waste. Magnetism also supports MRI, computer hard drives, tape recording, detection of inhaled asbestos, research on brain activity, and the levitation of high-speed trains. Work on magnetic containment for fusion energy is also ongoing.

Magnetic Poles and Everyday Uses

magnetism

Magnetism appears in many everyday objects, from toys and hangers to elevators, doorbells, and computer devices. Magnets have two poles, called north and south. Like poles repel each other, while unlike poles attract. Both poles can also attract unmagnetized iron. A single magnetic pole cannot be isolated, because every part of a magnet contains both a north pole and a south pole. A compass needle is a simple example of a magnet. It is a thin bar magnet suspended at its center, so it can turn...

magnetic fields

Magnetic Force on Moving Charges

Magnetic force on moving charges depends on motion, charge, and field direction. A moving charge or a current creates a magnetic field in the space around it, along with its electric field. That magnetic field can then push on other moving charges or currents in the field. A magnetic field is a vector field, so it has direction as well as strength. At any point, the field direction is the direction a compass needle’s north pole points. The field strength is defined from the force a charged...

magnetic field lines

Reading Magnetic Field Lines

Magnetic field lines show the direction and strength of a magnetic field. They make it easier to picture how a magnet acts in space. Each line forms a closed loop around the magnet. For a bar magnet, the field lines leave the north pole and curve around to the south pole. They then continue through the magnet back to the north pole. This loop has no beginning or end. Magnetic field lines follow clear rules. The magnetic field points tangent to a field line at any point. A small compass points...

magnetic flux

Magnetic Flux Through Surfaces

Magnetic flux through a surface describes how much magnetic field passes across that surface. It is measured in weber (Wb), the SI unit for magnetic flux. Magnetic flux is a scalar quantity, not a vector. Three factors shape magnetic flux. They are the magnetic field strength B, the area the field crosses, and the orientation of the field relative to the surface. For a small area element dA, the flux depends on the part of the magnetic field that is normal, or perpendicular, to that element at...

motion of a charged particle in a magnetic field

motion-of-a-charged-particle-in-a-magnetic-field

Charged Particle Paths in Magnetic Fields

A charged particle in a magnetic field follows a path that depends on the direction of its velocity. When the field is uniform and the particle moves perpendicular to it, the magnetic field is the main factor that controls the motion, especially in a vacuum. The magnetic force is always perpendicular to the direction of motion, so the particle curves into a circle. Because the force stays perpendicular to velocity, it does no work on the particle. The kinetic energy and speed stay constant...

magnetic force

Magnetic Fields and Moving Charges

Magnetic fields and moving charges create magnetic force. A moving electric charge, or a current made of many moving charges, produces a magnetic field. When another current or moving charge enters that field, it feels a magnetic force in response. At the atomic level, magnetic forces come from interactions between moving electrons in the atoms of two bodies. The strength of magnetic force depends on several factors. It increases with the size of the charge and with the strength of the...

magnetic force on a current-carrying conductor

magnetic-force-on-a-current-carrying-conductor

Current and Magnetic Field Around a Wire

A current-carrying wire creates a magnetic field around it, and moving charges feel a force in that field. Because the magnetic field produced by moving charges is proportional to current, the wire itself acts as a source of magnetic field. A compass placed near the wire shows this effect by lining up tangentially around the wire. The magnetic field around a straight wire forms concentric circular loops. The right-hand rule helps determine the direction of those loops. If the thumb points in...

magnetic force on current-carrying wires: example

magnetic-force-on-current-carrying-wires-example

Balancing Weight with Magnetic Force

Magnetic force can balance the weight of a current-carrying wire when the wire sits in a magnetic field. Moving charges in the wire feel a force, so the wire itself can be pushed upward or downward. This example uses a flexible wire that is 40 cm long and has a mass of 10 g. It is held in a horizontal position inside a constant 0.40 T magnetic field. The goal is to find the current needed to remove the tension in the supporting leads. To do that, a free-body diagram is drawn first. The diagram...

force on a current loop in a magnetic field

force-on-a-current-loop-in-a-magnetic-field

Current Loops and Torque in Motors

Current loops in a magnetic field create the torque that drives a DC motor. A DC motor converts electrical energy into mechanical work. In a motor, wire loops sit inside a magnetic field. When current flows through the loops, the magnetic field pushes on them and makes the shaft rotate. The current is reversed when the loop lines up with the magnetic field. This keeps the torque on the loop going in the same direction. A commutator and brushes handle this reversal. The commutator switches the...

torque on a current loop in a magnetic field

torque-on-a-current-loop-in-a-magnetic-field

Current Loop Torque in Electric Motors

Current loop torque in electric motors shows how magnetic force can make a wire loop rotate. In an electric motor, loops of wire sit between magnets in a magnetic field. When current flows through the loops, the field applies torque. This rotation turns a shaft and converts electrical energy into mechanical energy. A rectangular current-carrying loop with N turns in a uniform magnetic field has zero net force. Even so, it can still experience net torque. The torque depends on the current I,...

the hall effect

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...

thomson's e/m experiment

Electron Speed Selector in Thomson’s Tube

A velocity selector uses electric and magnetic fields to choose charged particles with one speed from a beam. Many beams from a heated cathode contain particles moving at different speeds, so this setup helps produce a uniform beam. The electric and magnetic fields are perpendicular to the particle’s motion and to each other. In this arrangement, a particle with charge q, speed v, and mass m enters from the top. The magnetic field points into the plane of the paper, and the electric field...

key terms and concepts

Learn how magnetic poles attract and repel, how compasses work, and how magnetism powers motors, generators, MRI, and more in everyday life.

Magnetic Poles and Everyday Uses | JoVE K12

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JoVE Core Física presenta la teoría y la aplicación de conceptos físicos fundamentales, como la cinemática, dinámica, mecánica de fluidos, estática, ondas y acústica, mediante animaciones audiovisuales concisas y fáciles de entender. Además, los vídeos de científicos en acción muestran la aplicación de los conceptos relacionados en experimentos de investigación clásicos y originales, realizados en laboratorios de todo el mundo.

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Ohio’s Learning Standards and Model Curriculum

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Igneous, Metamorphic And Sedimentary Rocks

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PS.9

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PH.7

PH.7.a

PH.7.b

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4.2.2 9C.3.2.2.1

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Waves and Their Applications in Technologies for Information Transfer

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New York State Science Learning Standards

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Electromagnetism

Position and Displacement

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Average and Instantaneous Velocity Vectors

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Acceleration Vectors

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Electrical Current

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Resistivity

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Ohm's Law

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Construct an explanation to compare simple series and parallel circuits in terms of Ohm's Law.

PS.PSc.6.2

Continuity Equation

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Boundary Conditions for Current Density

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Electrical Conductivity

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PS.PSc.6.3

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Magnetic Field Lines

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Magnetic Flux

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Motion Of A Charged Particle In A Magnetic Field

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Magnetic Force

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Magnetic Force On A Current-Carrying Conductor

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Magnetic Force On Current-Carrying Wires: Example

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Use models to explain magnetism in terms of domains, interactions of poles, and magnetic fields.

Analyze motion in terms of speed, velocity, acceleration, and momentum.

Magnetic Poles and Everyday Uses

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