Light from a point source in air falls on a convex curved surface of radius 20 cm and refractive index 1.5. If the source is located at 100 cm from the convex surface, the image will be formed a t____ cm from the object.
Physics · Geometrical optics · refraction due to curved surface
JEE Mains 2024 31 Jan Evening Shift

Question

Light from a point source in air falls on a convex curved surface of radius 20 cm and refractive index 1.5. If the source is located at 100 cm from the convex surface, the image will be formed a t____ cm from the object.

Physics · Geometrical optics · refraction due to curved surface

JEE Mains 2024 31 Jan Evening Shift

G1 Physics · Accepted Answer

For refraction at a spherical surface: μ₂/v - μ₁/u = (μ₂ - μ₁)/R Here, μ₁ = 1 μ₂ = 1.5 u = -100 cm R = +20 cm Therefore, 1.5/v - 1/(-100) = (1.5 - 1)/20 1.5/v + 0.01 = 0.025 1.5/v = 0.015 v = 100 cm Distance of image from object: = 100 + 100 = 200 cm