Magnetic field frequencies? | Physics Forums
Jul 26, There is a wonderful connection between c, the speed of light in a vacuum, We can go the other way, and use a magnetic field to produce a current, by an electromagnetic wave is proportional to the frequency of the wave. and different frequencies have different characteristics to us. It is all about changing electric and magnetic fields as opposed to static ones. I am looking at some practical, visual example of their relationship, if possible. An electromagnetic field is a physical field produced by electrically charged objects. It affects The electric field is produced by stationary charges, and the magnetic field by moving charges (currents); these two are often Planck's relation links the photon energy E of a photon to its frequency ν through the equation: E = h ν.
From the scope of classical electromagnetism Maxwell equations it's not so valid to discuss the existence of photons. Electromagnetic radiation is the propagation of time dependent coupled electromagnetic fields- by coupled I mean that one field has a phase relation with the other.
This result comes from solving the Maxwell equations, the equations of motion for classic light. This radiation carries energy and momentum in the fields and these fields exert a force on object via a force called Lorentz force https: So classical light can exert a force, but it's just to small to feel. When the light of the Sun heats you on a hot day, a force is exerted on your body on a molecular level, this force translate in work is the energy your body cells gain and so they warm up.
You can also think of visible light of lasers, where a highly energetic beam concentrated can do real damage to an object or the case of gamma radiation that can damage your DNA.
Magnetic Fields & Radio Frequency
If you now take quantum mechanical considerations you can think of light being quantized, but to do that properly one should quantize the electromagnetic field. A simpler approach is to treat the interacting particles electrons for example as quantum mechanical and the interaction between them taken as granted to be the electromagnetic potentials.
Anyway, you may consider photons but these particles are not particles in the sense of a concrete classical body, since they describe a field.
This is what induced emf is all about.
A steadily-changing magnetic field can induce a constant voltage, while an oscillating magnetic field can induce an oscillating voltage. Focus on these two facts: An electromagnetic wave such as a radio wave propagates outwards from the source an antenna, perhaps at the speed of light.Magnetic Field of a Wire
What this means in practice is that the source has created oscillating electric and magnetic fields, perpendicular to each other, that travel away from the source. The E and B fields, along with being perpendicular to each other, are perpendicular to the direction the wave travels, meaning that an electromagnetic wave is a transverse wave. The energy of the wave is stored in the electric and magnetic fields.
Magnetic field frequencies?
Properties of electromagnetic waves Something interesting about light, and electromagnetic waves in general, is that no medium is required for the wave to travel through.
Other waves, such as sound waves, can not travel through a vacuum.
An electromagnetic wave is perfectly happy to do that. An electromagnetic wave, although it carries no mass, does carry energy.
Electromagnetic field - Wikipedia
It also has momentum, and can exert pressure known as radiation pressure. The reason tails of comets point away from the Sun is the radiation pressure exerted on the tail by the light and other forms of radiation from the Sun.
The energy carried by an electromagnetic wave is proportional to the frequency of the wave. The wavelength and frequency of the wave are connected via the speed of light: Electromagnetic waves are split into different categories based on their frequency or, equivalently, on their wavelength.
In other words, we split up the electromagnetic spectrum based on frequency.
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Visible light, for example, ranges from violet to red. Violet light has a wavelength of nm, and a frequency of 7. Red light has a wavelength of nm, and a frequency of 4.
Any electromagnetic wave with a frequency or wavelength between those extremes can be seen by humans.
Visible light makes up a very small part of the full electromagnetic spectrum. Electromagnetic waves that are of higher energy than visible light higher frequency, shorter wavelength include ultraviolet light, X-rays, and gamma rays. Lower energy waves lower frequency, longer wavelength include infrared light, microwaves, and radio and television waves.