A light ray is incident on a glass sphere of reflective index `mu = sqrt3` at an angle of incidence `60^(@)` as shown in Fig. Find the angles r, `r^(')` e and the total deviation after two refractions.

Explanation

Applying Snell's law `1sin 60^(@) = sqrt(3) sinr`
`rArr r = 30^(@)`
From symmetry `r' = r = 30^(@)`
Again applying Snells law at secound surface `1 sin e = sqrt(3) sinr`
`rArr e = 60^(@)`
Deviation at first surface `= I - r = 60^(@) - 30^(@) = 30^(@)`
Deviation at secound surface `= e - r' = 60^(@) - 30^(@) = 30^(@)`
Therefore total deviation `= 60^(@)`