Question

(a) Show using a proper diagram how unpolarised light can be linearly polarised by reflection from a transparent glass surface.
(b) The figure shows a ray of light falling normally on the face $AB$ of an equilateral glass prism having refractive index $\frac{3}{2}$, placed in water of refractive index $\frac{4}{3}$. Will this ray suffer total internal reflection on striking the face $AC$? Justify your answer.

Answer 1

A. When Unpolarised light is incident on glass surface the electric vectors that are oscillating along a direction perpendicular to aligned molecules will pass through. Thus incident light gets polarised.

B. Total internal reflection on AC, if $i_c<{60}^o$

${\mu }_{1}Sin{i}_c={\mu }_{2}sin{90}^o$

$\frac{3}{2}Sin{i}_c=\frac{4}{3}\left(1\right)$

$Sin{i}_c=\frac{8}{9}$

$i_c=si{n}^{-1}\left(\frac{8}{9}\right)$

so $i_c>{60}^o$

So total internal reflection does not take place