As I know, every electromagnetic wave has magnetic and electric field component (perpendicular to the direction of wave). I have a doubt about this, as a hot iron bar also emits EM waves, and as result it cools down. If that's the case, then how are magnetic and electric components are produced without a charge and a magnet?


Charges and magnets are not the only way to produce electric/magnetic fields. For example magnetic fields can also be produced by moving charges, a.k.a currents, or by changing electric fields. Similarly Electric fields can be produced by changing magnetic fields.

When charges accelerate (or decelerate) they can produce disturbances in the electric and magnetic fields using the effects I mentioned above. A hot iron bar contains many accelerating charges because thermal energy causes the particles to bump into eachother making them change direction. If the electric and magnetic field wouldn't interact that would be the end of the story. The electric and magnetic field would just fall of like 1/distance^2 and just a few centimeters away it would be near impossible to detect the motion of the particles. The interactions of the electric/magnetic fields cause a sort of feedback loop that allows EM waves to travel for long distances and that's why you can see the metal glowing hot.

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  • $\begingroup$ Thx a lot ...from India ... $\endgroup$ – Satyam obroy Jul 26 '18 at 17:26

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