What are the Polaroids and what are the uses of Polaroids ?

 Polaroids :-

       (In 1934 E.H.Lamb developed a polarizer known as polaroid )

    It is a large sheet of synthetic material packed tiny crystals of a dichroic substance oriented parallel to one another, so that it transmits light only in one direction of the electric vector

       Dichroic Crystal (substance):- The property by which some doubly refracting crystals absorb the ordinary rays (O-rays) completely and extraordinary rays whose direction is parallel to the axis while passing through the crystal, is called Dichroism. The substance possessing dichroism property is called Dichroic Substance.

  Uses of  Polaroids :-

(1) In motor car head lights to remove headlight glare.

(2) In three dimensional movie cameras.

(3) To produce and analyse polarized light.

(4)  It is used as filter in photographic cameras.

(5)  In windows of aeroplanes to control the amount of light.

(6)  In polarizing sunglasses (goggles) to protect the eyes from the glare of sunlight.

(7)  They are used to improve colour contrast in old oil paintings.

(8)  They are used in calculators, watches, monitors of laptops which have LCD screens.