Question

A ray `PQ` incident on face `AB` of a prism `ABC`, as shown in Fig., emerges from the face `AC` such that `AQ = AR`. Draw the ray diagram showing the pasage of the ray through the prism. If the angle of prism is `60^@` and refractive index of the material of the prism is `sqrt(3) ,` determine the values of angle of incidence and angle of deviation.
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Answer 1

As the refracted ray passes such that `AQ = AR`, it must go parallel to the base of the prism suffering minimum deviation.
`r = A//2 =(60)/(2) = 30^@`
`mu = (sin i)/(sin r) = (sin i)/(sin 30^@)`
`:. sin i= mu sin 30^@ = sqrt(3) xx (1)/(2)`
`i= 60^@`
As `i+ e = A + delta_m`
`2 i= 60^@ + delta_m, delta_m = 2 i-606@ = 120^@ - 60^@`
`delta_m = 60^@`.