Question

Calculate the angle of incidence of light ray incident on surface

of a plastic slab of refractive index v3, if the angle of refraction
is 30°
​

Answer 1

`from \: snell {}^(.) s \: law : \\ n = ( \sin(i) )/( \sin(r) ) \\ √(3) = ( \sin(i) )/( \sin(30 \degree) ) \\ \sin(i) = √(3) * \sin(30 \degree) \\ \sin(i) = 0.866 \\ i = { \sin}^( -1 ) (0.866) \\ i = 60 \degree`