Question

How are the electromagnetic waves produced? What is the source of energy of these waves? Write mathematical expressions for electric and magnetic fields of an Electromagnetic wave propagating along the Z – axis. Write any two important properties of electromagnetic waves.

Answer 1

Hint: The phenomenon of electromagnetic induction says that changing magnetic fields at a point produces an electric field at the same point. In the same way, changes in electric fields at a point produce magnetic fields at the same point. This concluded that variation in electric and magnetic fields are perpendicular to each other.


Complete step by step answer:
The electromagnetic waves are produced by accelerated charges. Any accelerated charge is a charged particle that is oscillating about a position and it is known to be the source of electromagnetic radiation or waves.
Some of the properties of electromagnetic waves are given below,
In electromagnetic waves, electric and magnetic field vectors are at right angles or perpendicular to each other and also perpendicular to the direction of propagation.
They have wave character and propagate through free space without any medium. They are also transverse in nature.
Variation of maxima and minima of both fields occur simultaneously. The energy in an Electromagnetic wave is equally divided between the field vectors. They are chargeless and are not deflected by any field.
The existence of electromagnetic waves was confirmed by Hertz in 1888. The mathematical expression for electric and magnetic fields of a wave propagating along Z-axis can be written as,
Electric field, ${ E }_{ x }={ E }_{ 0 }\sin { \left( kz-\omega t \right) }$
Magnetic field, ${ B }_{ y }={ B }_{ 0 }\sin { \left( kz-\omega t \right) }$

Note: Hertz produced electromagnetic waves of frequency about 5 ×107 Hertz. The distribution of electromagnetic waves is based on their wavelength or frequency and is called the electromagnetic spectrum.