Question

When light rays are incident on a prism at an angle of `45^(@)`, the minimum deviation is obtained. If refractive index of the material of prism is `sqrt(2)`, then the angle of prism will be
A. `30^(@)`
B. `75^(@)`
C. `90^(@)`
D. `60^(@)`

Answer 1

Correct Answer - B
(d) refractive index of prism,
`µ=(sin""(A+delta_(m))/2)/(sin""A/2)rArri=45^(@)=(A+delta_(m))/2`
So, `sin45^(@)/sin(A//2)=sqrt2`
So, `1/2=sin""A/2rArrA=60^(@)`