Explain linearly polarized waves and give it definition.

Explanation

Consider holding a long string that is hel horizontally, the other end of which is to b fixed.
If we move the end of the string up and dowi in a periodic manner. A wave is generate propagating in the + x-direction as shown in figure (a).

The curves represent the displacement of a string at t = 0 and at `t=Deltat` respectively when this sinusoidal wave is propagating in the + x direction. This is shown in figure (a).
In figure (b) the curve represents the time variation of the displacement at x = 0 when a sinusoidal wave is propagating in the + xdirection.

The displacement of the wave in the + xdirection occurs in the y-direction so its equation,
`y(x,t)=asin(kx-omegat)`
where a = amplitude of wave
`omega=2piv` angular frequency of wave
`k=(2pi)/(lamda)` wave vector and
`lamda=(2pi)/(k)` wavelength
According to this equation the displacement of particle of string (in y-direction) is at right angles to the direction of propagation of the wave, so it is known as a transverse wave. Here displacement is in the y-direction so it is called y-polarised wave.
Since each point on the string moves on a straight line, so this wave is called a linearly polarised wave.
The string always remains confined to the xyplane and therefore it is called as a plane polarised wave.
If we can consider the vibration of the string in the xz-plane generating a 2-polarised wave whose displacement will be z(x,t) `=asin(kx-omegat)`.
This is also the linearly polarised wave and it is transverse wave.