The refracting angle of a glass prism is `30^@.` A ray is incident onto one of the faces perpendicular to it. Find the angle `delta` between the incident ray and the ray that leaves the prism. The refractive index of glass is `mu=1.5.`

Options

A. `18^(@)36'`
B. `20^(@)30^(@'`
C. `18^(@)`
D. `22^(@)1'`

Answer

A

Explanation

For surface `AC(1)/(mu) (sin 30^(@))/(sin e)impliessin e =mu si n30^(@)`
`impliessin e =1.5xx(1)/(2)=0.75`
`implies e=sin^(-1)(0.75)=48^(@)36'`
From figure `delta=e-30^(@)`
`=48^(@)36'-30=18^(@)36'`