Question

A ray of light is incident at an angle of `60^(@)` on one face of a prism which has refracting angle of `30^(@)` . The ray emerging out of the prism makes an angle of `30^(@)` with the incident ray. If the refractive index of the material of the prism is `mu=sqrt(a)` , find the value of a .

Answer 1

Correct Answer - 3
Given `i+60^(@), delta=30^(@) and A=30^(@)`.
We have `delta=i+e-A`
Form Eq. (i), we get
`30^(@)=60^(@)+e-30^(@) or e=0`
So `r_(2)` is also zero, then `r_(1)=A=30^(@)`
So `mu=(sini)/(sinr_(1))=(sin60^(@))/(sin30^(@))=sqrt(3)`
Hence the value of `a=3`.