A ray of light is incident at `60^(@)` on one face of a prism of angle `30^(@)` and the emergent ray makes `30^(@)` with the incident ray. The refractive index of the prism is

Options

A. 1.732
B. 1.414
C. 1.5
D. 1.33

Answer

A

Explanation

(a) As, A+ `delta`=i+e
`rArr 30^(@) + 30^(@) = 60^(@)` + e
Angle of emergence , e=`60^(@)-60^(@)`=0
`r_(1)=A=30^(@)`
`therefore` Refractive index, `mu=(sin i)/(sin r)=sin 60^(@)/(sin 30^(@))=sqrt3=1.732`