Question
(i) State law of Malus.
(ii) Draw a graph showing the variation of intensity (I) of polarised light transmitted by an analyser with angle (
) between polarizer and analyser.
(iii) What is the value of refractive index of a medium of polarising angle 60o?
(i) State law of Malus.
(ii) Draw a graph showing the variation of intensity (I) of polarised light transmitted by an analyser with angle () between polarizer and analyser.
(iii) What is the value of refractive index of a medium of polarising angle 60o?
Solution
i) Law of Malus states that when a completely plane polarised light beam is incident on an analyser, the intensity of the emergent light varies as the square of the cosine of the angle between the plane of transmission of the analyser and the polariser.
I = Io cos2
ii) The variation of intensity (I) of polarised light transmitted by an analyser with angle 
.
iii) According to the Brewster's law, we have
The refractive index of the material is 1.73
