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

Options

A. `90^(@), sqrt(3)`
B. `0^(@), sqrt(3)`
C. `0^(@), sqrt(2)`
D. `90^(@), sqrt(2)`

Answer

B

Explanation

Here `i=60^(@),A=30^(@),delta=30^(@)`
As `delta=(i+e)-A`
`:.30=(60+e)-30^(@)`
or `e=0^(@)`
As `e=0^(@)`,so `r_(2)=0^(@)`
But `A=r_(1)+r_(2)`
or `30^(@)=r_(1)+0^(@)`
`:.r_(1)=30^(@)`
`mu=(sini_(1))/(sinr_(1))=(sin60^(@))/(sin30^(@))=((sqrt(3))/(2))/((1)/(2))=sqrt(3)`