Question

A ray incident on a droplet of water from air at an angle of incidence `30^(@)` undergoes two reflections and emerges. If the deviation suffered by the ray is minimum then the requried refractive index of the drop `mu=sqrt(x)`. Find the value of x.

Answer 1

Correct Answer - 7
`delta=i-r+180-2r+i-r`
`1sini=musinr`
`(ddelta)/(di)=0`
`cosi=sqrt((mu^(2)-1)/(8))`