question_answer

Un-polarised light is travelling from a medium of refractive index 2 to a medium of refractive index 3. The angle of incidence is\[60{}^\circ \]. Then

A)  Reflected light will be partially polarized

B)  reflected/light will be plane polarised in a plane perpendicular to plane of incidence

C)  refracted light will be plane polarised in a plane perpendicular to plane of incidence

D)  refracted light will be plane polarised in a plane parallel to plane of incidence

Correct Answer: A

Solution :

 Consider the situation shown below Brewsters angle for two media is given by \[\tan {{i}_{B}}=\frac{{{n}_{2}}}{{{n}_{1}}}=\frac{3}{2}\] \[\Rightarrow \] \[{{i}_{B}}={{\tan }^{-1}}(3/2)\approx 56{}^\circ \] Clearly, \[i=\theta \ne {{i}_{B}}\] Thus, reflected light is not plane polarized. It will be partially polarized.