A glass prism of refracting angle `60^(@)` and of refractive index 1.6, is immersed in water (refractive index is 1.33). What is its angle of minimum deviation ? `[sin 36.87^(@) = 0.6]`

Explanation

`"Here", A = 60^(@), a^(mu)g = 1.6,a^(mu)g = 1.33`
`therefore " " w^(mu)g = (a^(mu)g)/(a^(mu)w) = (1.6)/(1.33) = 1.2`
Let angle of minimum deviation for the immersed is `delta_(m)`.
`therefore " " w^(mu)g = sin((A + delta_(m))/(2))/(sin""(A)/(2))`
`or, " " 1.2 = sin((60^(@) + delta_(m))/(2))/(sin(60^(@))/(2)) or, 1.2 xx sin30^(@) = sin""(60^(@) + delta_(m))/(2)`
`or, " " sin""(60^(@) + delta_(m))/(2) = 1.2 xx (1)/(2) = 0.6 = sin36.87^(@)`
`or, " " (60^(@) + delta_(m))/(2) = 36.87^(@)`
`or, " " delta_(m) = 73.74^(@) - 60^(@) = 13.74^(@)`