A monochromatic light is incident on as equallateral prism at an angle `30^(@)` and emerge at an angle of `75^(@)`. What is the angle of deviation produced by the prism?

Explanation

Give: as the prism is equilateral.
`A = 60^(@) , l_(1) = 30^(@) , l_(2) = 75^(@)`
Equation for angle of deviation, `d = l_(1) + l_(2) - A`
Substituting the values, `d = 30^(@) + 75^(@) - 60^(@) - 45^(@)`
The angle of deviation produced is, `d - 45^(@)`