Question
Question: A ray of light falls on the surface of a spherical glass paper weight making an angle \(\alpha\) w...
A ray of light falls on the surface of a spherical glass paper weight making an angle α with the normal and is refracted in the medium at an angle β. The angle of deviation of the emergent ray from the direction of the incident ray is
A
(α−β)
B
2(α−β)
C
(α−β)/2
D
(α+β)
Answer
2(α−β)
Explanation
Solution

From figure it is clear that △OBC is an isosceles triangle,
Hence ∠OCB=β and emergent angle is α
Also sum of two in terior angles = exterior angle
∴ δ=(α−β)+(α−β)=2(α−β)