JEE Advanced2014PhysicsRay OpticsActual
A point source S is placed at the bottom of a transparent block of height 10 mm and refractive index 2.72. It is immersed in a lower refractive index liquid as shown in the figure. It is found that the light emerging from the block to the liquid forms a circular bright spot of diameter 11.54 mm on the top of the block. The refractive index of the liquid is
Options
- A1.21
- B1.30
- C1.36
- D1.42
Correct answer
C. 1.36
Step-by-step solution
tan θ C = r h = 5.77 10 ≈ 3 ⇒ θ C = 30 o ⇒ sin θ C = μ l μ b ⇒ μ l = 2.72 × 1 2 = 1.36