Question

A glass beaker has a solid, plano-convex base of refractive index 1.60, as shown in the figure. The radius of curvature of the convex surface (SPU) is 9 cm, while the planar surface (STU) acts as a mirror. This beaker is filled with a liquid of refractive index n up to the level QPR. If the image of a point object O at a height of ℎ (OT in the figure) is formed onto itself, then, which of the following option(s) is(are) correct?

• A. For $n = 1.42, ℎ = 50 \ cm$
• B. For $n = 1.35, ℎ = 36 \ cm$
• C. For $n = 1.45, ℎ = 65 \ cm$
• D. For $n = 1.48, ℎ = 85 \ cm$

Answer 1

Answer: (A), (B)

For $n = 1.42, ℎ = 50 \ cm$

Answer 2

The correct option is (A):For $n = 1.42, ℎ = 50 \ cm$ and (B):For $n = 1.35, ℎ = 36 \ cm$