Question

For a Prism, explain deviation and establish the relation δ = A (n-1).

Answer 1

Deviation through Prism— Angle of deviation produced by a prism is the angle between extended line on incident ray and emergent ray. It is represented by δ.

Snell's law for refracting surface AB—

Snell's law for refracting surface AC— 

According to prism's relation,

i + e = δ + A

Using eqⁿ (3) & (4)

Conclusion—Angle of deviation produced by a prism is equal to angle of prism times refractive index minus unity.