Describe classification of waves in detail with examples.

Explanation

All types of waves can be classified into following three categories.
(1) Mechanical Waves : "The waves which require an elastic medium for their propagation, are called mechanical waves.
For example : String waves, spring waves, water waves, sound waves seismic waves (propagating on the ground during earthquake) are all mechanical waves.
Here waves propagate because of elasticity property of medium.
(2) Electromagnetic Waves OR
Non-mechanical Waves : "The waves which do not require any medium for their propagation, are called non-mechanical waves. They are also called electromagnetic waves (because during their propagation, electric and magnetic fields oscillate periodically in mutually perpendicular directions in a plane perpendicular to direction of propagation of wave)".
For example, radiowaves, infrared light waves, visible light waves, ultraviolet light waves, X-ray and gamma rays are the examples of electromagnetic or nonmechanical waves. They can propagate in vacuum also. The light emitted from stars very far from us (hundreds of light years away from us) reaches to us after passing through vacuum in the inter - stellar space.
All types of electromagnetic waves have same speed in vacuum with a value`c =2.99 792458 xx 10 ^(8) m//s` (Which is a well known physical constant known as velocity of light in vacuum)
(3) Matter Waves : It has been proved experimentally that, "When a fundamental particle of mass m, moves with a velocity v, its motion can be described very well by a wave of wavelength `lamda = (h)/(mv)`
(Where h = Planck.s constant `=6.625 xx 10 ^(-34) (Js)."` Such waves are called "Matter Waves". (These waves were predicted by Louis De Broglie and so they are also known as De-Broglie waves).
Matter waves represent the motion of atom (smallest part of an element), molecule (smallest part of a compound, fundamental particles like electron, proton and neutron (which take part in the constitution of any matter). They interact and show their effect, quite similar to those shown by mechanical or non-mechanical waves. They have been employed in many devices, from basic to modern technology, for example stream of fast moving electrons is employed in electron microscope (which gives an image with magnification and clarity, greater than that produced by any light).