How Are Electric and Magnetic Fields Produced in Electromagnetic Radiations?

In summary, the conversation discusses the production of electric and magnetic fields at perpendicular angles in electromagnetic radiations. It is clarified that this only occurs in the 'far field' of a radiator and not up close due to energy storage. The simplest case is a plane EM wave in space. Additionally, it is mentioned that near an antenna, different modes can occur which are not always TEM.
  • #1
Confused mind
I have encountered a problem that how electric and magnetic fields at perpendicular to each other are produce in electromagnetic radiations?
 
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  • #3
Confused mind said:
I have encountered a problem that how electric and magnetic fields at perpendicular to each other are produce in electromagnetic radiations?
This is only the case in the 'far field' of a radiator. Right up close, the fields can have a range of relative angles around, say, a simple antenna. It is only when the fields have settled down at a distance and there is only energy being transferred and not stored (as in a Capacitor or Inductor). A plane EM wave in space is the simplest case.
 
  • #4
sophiecentaur said:
This is only the case in the 'far field' of a radiator. Right up close, the fields can have a range of relative angles around, say, a simple antenna.

Is that so? Huh. I never knew that. I thought the angle was always 90 degrees.
 
  • #5
Drakkith said:
Is that so? Huh. I never knew that. I thought the angle was always 90 degrees.
It is when the only wave is a progressive wave. In the standing wave region the fields will be the resultant of various traveling waves in different directions. Also, in waveguides, not all the modes are TEM, there are TE modes too. Coax is always TEM, though.
Near to an antenna you can get different modes which are not TEM and it happens, I think, when you have waves from different parts of the antenna, traveling in different directions.
 
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1. What are electromagnetic radiations?

Electromagnetic radiations are a type of energy that travels in the form of waves through space. They are created by the movement of electrically charged particles and can range from very long wavelengths, such as radio waves, to very short wavelengths, such as gamma rays.

2. How do electromagnetic radiations interact with matter?

Electromagnetic radiations can interact with matter in several ways. They can be absorbed, reflected, or transmitted through different materials depending on their frequency and the properties of the material. For example, visible light is mostly transmitted through glass, but absorbed by opaque objects like wood.

3. What are the health effects of electromagnetic radiations?

The health effects of electromagnetic radiations depend on their frequency and intensity. Some forms of electromagnetic radiations, such as ultraviolet and X-rays, can be harmful to living organisms at high levels of exposure. However, most forms of electromagnetic radiations, including visible light and radio waves, are not harmful to humans.

4. How are electromagnetic radiations used in technology?

Electromagnetic radiations have many practical applications in technology. For example, radio waves are used for communication, microwaves are used for cooking, and X-rays are used for medical imaging. Electromagnetic radiations are also used in devices such as lasers, solar panels, and radar systems.

5. How does the electromagnetic spectrum work?

The electromagnetic spectrum is a range of all types of electromagnetic radiations, organized by their frequency and wavelength. It includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. The spectrum starts with low-frequency, long-wavelength radio waves and ends with high-frequency, short-wavelength gamma rays.

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