Question

JEE mains Previous year question chapter :- Geometrical Optics​

Answer 1

Answer:

Option (d) is correct

Explanation:

We know that , angle of deviation for small prism

"D" = (μ - 1 )

For red light D₁ = (1.525 - 1)A

For green light D₂ = (1.520 - 1 ) A

• → D₁ /D₂ < 1

• D₂ > D₁

For the blue light, μ is greater that for red light ,

so D₂ >D₁

Answer 2

Explanation:

D₁ and D₂ be the angels of minimum deviation for red and blue lights respectively.

then,

refractive index of glass for red light, μ₁ = 1.520

refractive index of glass for blue light, μ₂ = 1.525

we know,

minimum deviation, D = (μ-1)A where A is the angle of prism.

→ D₁ = (μ₁-1)A

= (1.520-1)A

= 0.52A

and

→D₂ = (μ₂-1)A

= (1.525-1)A

= 0.525A

∴ D₂ > D₁