Solve que 36

Q36. A transparent thin film of uniform thickness and refractive index n₁ = 1.4 is coated on the convex spherical surface of radius R at one end of a long solid glass cylinder of refractive index n₂ = 1.5, as shown in the figure. Rays of light parallel to the axis of the cylinder traversing through the film from air to glass get focused at distance f₁ from the film, while rays fo light traversing from glass to air get focused at distance f₂ from the film. Then 

        
    (A) |f₁| = 3 R

    (B) |f₁| = 2.8 R

    (C) |f₂| = 2 R

    (D) |f₂| = 1.4 R