A ray of light is incident on a `60^(@)` glass prism at an angle of `60^(@).` Find the
the angle of emergence
the angle of deviation, given the refractive index of glass = 1.5.

Explanation

`A = 60 ^(@) i _(1) = 60 ^(@)`
`n _(g) = 1. 5`
At first face, `n = (sin i _(1))/( sin r _(1)) = ( sin 60^(@))/( sin r _(1))`
`1. 5= ( sin 60 ^(@))/( sin r _(1))`
`sin r _(1) = (sqrt3 //2)/( 1. 5) = 0. 5773`
`therefore r _(1) = 35 ^(@) 16.`
`therefore r _(2) = A - r _(1) = 60 ^(@) - 35 ^(@) 16. = 24 ^(@) 44.`
At the second face,
`n = (sin i _(2))/( sin r _(2))`
`sin i _(2) = n sin r _(2) = 1. 5 sin 24 ^(@) 44.`
`sin i _(2) = 1. 5 xx 0. 41 84 = 0. 6276`
`i _(2) = 38^(@) 52. ~~ 39^(@)`
Angle of deviation `delta = i _(1) + i _(2) - A`
`= 60 ^(@) + 39 ^(@) - 60 ^(@) = 39 ^(@)`