Question

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. ( angle of prism is 30)

Answer 1

Refer to Fig. As the ray `PQ` falls normally on face `AB`, at `angle I = 30^(@)`. It will be refracted along `RS` at on `AC` at `angle r`. The refracted ray emerge from face `AC` 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^(@)`