A thin prism with angle 5^ of refractive index 1.72 is combined with another prism of refractive index 1.9 to produce dispersion without deviation. The angle of second prism is _ _ _ _ .

Step-by-step solution

For dispersion without deviation, the condition is ( ₁ - 1)A₁ + ( ₂ - 1)A₂ = 0 . Substituting values: (1.72 - 1) 5 + (1.9 - 1) A₂ = 0 0.72 5 + 0.9 A₂ = 0 3.6 + 0.9 A₂ = 0 A₂ = -4° The magnitude of the second prism angle is 4°.