Question

Question #72152

Answer 1

Electromagnetic waves are non elastic waves in the sense that they don't really need a material medium for their propagation like sound waves do.

EM waves, as I shall call them are basically perpendicularly oscillating electric and magnetic fields propagating in space. The Oscillating fields oscillate transversely i.e. perpendicular to the direction of propagation.

Their velocity in a particular medium is determined thus by the electrical and magnetic properties of the medium.
In vacuum, they propagate with a velocity approximately given as
`c = 3*10^8 ms^(-1)`

In presence of material medium their velocity is smaller than this and is given as

`v = (epsilon*mu)^(-1/2)`
where
`ε` is the electrical permittivity and
`μ` is the magnetic permeability.