Q15 of 26 Page 1

(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 3/2 , placed in water of refractive index 4/3 . Will this ray suffer total internal reflection on striking the face AC ?


a)



b) The angle of incidence, of the ray, on striking the face AC is


i = 60° (as from figure).



Total internal reflection will only take place when the angle of incidence i is greater than critical angle ic.


We know that condition for total internal reflection is



Where μ is the relative refractive index of glass, with respect to the surrounding water. Therefore ,



Therefore




Since ic is greater than the incident angle i, total internal reflection will not take place.


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