A ray of light is incident normally on one of the face of a prism of angle 30° and refractive index 2.  The angle of deviation will be

A=30∘,μ=2. As we know  A=r1+r2=0+r2⇒A=r2 Applying Snell’s law for the surface AC  1μ=sin⁡r2sin⁡e=sin⁡Asin⁡e ⇒12=sin⁡30∘sin⁡e⇒e=45∘ δ=e−r2=45∘−30∘=15∘