`(a)` State law of Malus.
`(b)` Draw a graph showing the variation of intensity `(I)` of polarised light transmitted by an analyser with angle `(theta)` between polariser and analyser.
`(c )` What is the value of refractive index of a medium of polarising angle `60^(@)` ?

Explanation

`(i)` When a beam of completely plane polarized light is passed through analyser, the intensity I of the transmitted light varies directly, as the square of cosine of the angle `'theta'` between the transmission direction of polariser and analyser . i.e.,
`I=I_(@)cos^(2)theta`
`(ii)` Variation of intensity with `(theta)`

`(iii) mu=tan tp=tan60^(@)=sqrt(3)`