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Question
The reflected light is found to be plane polarised when an unpolarized light falls on a denser medium at 60° with the normal. Find the angle of refraction and critical angle of incidence for total internal reflection in the denser to rarer medium reflection.
Solution
60° + r + 90° = 180°
60° + r = 90°
r = 30°
Angle of refraction = 30°
c = ?
`mu = 1/(sin "c")`
`mu = (sin "i")/(sin "r")`
`mu = (sin 60)/(sin 30)`
= `(sqrt3/2)/(1/2)`
`= sqrt3`
`mu = 1/(sin "c")`
sin c = `1/mu`
sin c = `1/sqrt3`
c = `sin^-1 (1/sqrt3)`
c = 35.15°
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