Answer this question.

Answer this question. Explain the ASS/3-312-A 1 A force F construction and working of a polaroid. 4 I I I I II I I I II I I I I I I I I I I I Ill I I I I I II = (2 i + 3 j) N displaces a body through S = (i + j) m Calculate the amount of work done. vTg An electric dipole consists Of two equal and unlike charges ± 2 s by a distance 10 nm. Calculate the potential energy Of the dipole whel placed in an electric field E — parallel to field lines. ± 2 10 I E 100 NC-I Give any two measures which may reduce nuclear radiations in our envir( *råg f%u-r I Draw diagrams to show a (i) forward biased p-n junction (ii) a reversi biased p-n junction. (i) p-n (ii) p-n qfü

A Polaroid is a material which polarises light. The phenomenon of selective absorption is made use of in the construction of polariods. There are different types of polaroids. A Polaroid consists of micro crystals of herapathite (an iodosulphate of quinine). Each crystal is a doubly refracting medium, which absorbs the ordinary ray and transmits only the extra ordinary ray. The modern polaroid consists of a large number of ultra microscopic crystals of herapathite embedded with their optic axes, parallel, in a matrix of nitro - cellulose. Recently, new types of polariod are prepared in which thin film of polyvinyl alcohol is used. These are colourless crystals which transmit more light, and give better polarisation.