can you explain the difference b/w polarised and unpolarised in detail by showing some videos?
The phenomenon of restricting the vibrations of the light (electric vector ) in a particular direction, perpendicular to the direction of wave motion is called polarization of light.
See the following picture.
At 1st the unpolarized beam enters the polarizer which polarizes the light, the polarized light when enters the analyzer aligned at the same angle as the polarizer , does not change the orientation of the light.
However when you see the 2nd diagram, the angle of analyzer changes and it is 900 to that of the polarizer. At this configuration, the polarized light does not pass through the analyzer.
The intensity of light follows law of Malus.
https://www.meritnation.com/videos/play/A0ykkZwuXzzBrnD21EBz48fzSYJUNVj@MXBTXSBfVG0!/Wave%20Optics/
Here one of the slits act as polarizer and the other acts as an analyzer. As you can see from the video, as the angle varies between polarizer and analyzer, the intensity of light coming from the book also changes.
When the angle is 900, you can see that the intensity is 0 and the book is no more visible.