What is the difference between the Electromagnetic radiation and an electromagnetic field?

What is the difference between the Electromagnetic radiation and an electromagnetic field or electromagnetic spectrum?



What is electomagnetic radiation ? Like what type of radiation are they talking about?



And what is spectrum of electomagnetic radiation mean?



Why do people call electronic devices or electrical devices radio frequency or part of the spectrum when it is not Radio,Microwave,Infrared,Visible, Ultraviolet,X-rays ,Gamma rays.



I know every electronic devices when turn on or electrical devices when turn on have Electromagnetic field or any electric current have a Electromagnetic field .What is the difference between the Electromagnetic radiation and an electromagnetic field?
You actually know more about it than you may think! The electromagnetic (EM) spectrum is just a name that scientists give a bunch of types of radiation when they want to talk about them as a group. Radiation is energy that travels and spreads out as it goes-- visible light that comes from a lamp in your house and radio waves that come from a radio station are two types of electromagnetic radiation. Other examples of EM radiation are microwaves, infrared and ultraviolet light, X-rays and gamma-rays. Hotter, more energetic objects and events create higher energy radiation than cool objects. Only extremely hot objects or particles moving at very high velocities can create high-energy radiation like X-rays and gamma-rays.

Here are the different types of radiation in the EM spectrum, in order from lowest energy to highest:





The electromagnetic field is a physical field produced by electrically charged objects. It affects the behavior of charged objects in the vicinity of the field.

The electromagnetic field extends indefinitely throughout space and describes the electromagnetic interaction. It is one of the four fundamental forces of nature (the others are gravitation, the weak interaction, and the strong interaction). The field propagates by electromagnetic radiation; in order of increasing energy (decreasing wavelength) electromagnetic radiation comprises: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

The field can be viewed as the combination of an electric field and a magnetic field. The electric field is produced by stationary charges, and the magnetic field by moving charges (currents); these two are often described as the sources of the field. The way in which charges and currents interact with the electromagnetic field is described by Maxwell's equations and the Lorentz force law.

From a classical perspective, the electromagnetic field can be regarded as a smooth, continuous field, propagated in a wavelike manner; whereas, from a quantum mechanical perspective, the field is seen as quantised, being composed of individual photons.What is the difference between the Electromagnetic radiation and an electromagnetic field?
That's a lot of questions. Let's see if we can get through them.



An electromagnetic field is the combination of two fields, an electric field and a magnetic field. They are oscillating, and are coupled together - an oscillating electric field causes an oscillating magnetic field, and vice versa. Electromagnetic radiation is the consequence of this - the fields move with the speed of light and 'radiate' from a source.



I'm not sure what you mean by 'Like what type of radiation are they talking about'. Anything that is radiated, that emanates from an object, is radiation. It's nothing to do with radioactivity - well, gamma is a specific type of electromagneitc radiation, but alpha and beta are not.



The electromagnetic spectrum is the combination of all types of electromagnetic radiation. We artificially divide the spectrum up into categories based on the effects of the radiation and the causes of the radiation, but in essence there's not much difference between a low-frequency radio wave and a high-frequency gamma ray, apart from the frequency. They're both still oscillating electric and magnetic fields.



Electronic devices which operate with clock cycles in the MHz and GHz range can be referred to as radio-frequency devices. There are two reasons for this. The first is that radio waves have these sorts of frequencies - for example, FM is around 100MHz. The second is that changes in voltage level in devices propagate as electromagentic waves in the device - the eletrons don't move so fast, but the wire strips and cables guide the energy for change as electromagnetic radiation.