A ray `PQ` is incident normally on the refracting face of the prism `BAC` made of material of refractive index `1.5`. Complete the path of ray through the prism. From which face will the ray emerge and at what angle ? Justify your answer.

Explanation

As the ray `PQ` falls normally on face normally on face `AB`, it passes undeviated falling on AC at `/_ i= 30^@`. It will be refracted along `RS` at `/_ r`. The refracted ray emerges from face `AC` of prism.
As refraction occurs from denser to rarer medium.
`:. mu = (sin r)/(sin i), sin r = mu sin i`
=`1.5 sin 30^@ = 0.75`
`r = sin^-1(0.75) = 48.6^@`.
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