STANDARD Physics Lens Maker's Formula MCQ Question
The radii of curvature of the surfaces of a double convex lens are 20 cm and 40 cm respectively, and its focal length is 20 cm. What is the refractive index of the material of the lens?
5/2
1/3
5/3
1/5
Correct Answer
Detailed Explanation
Using the lens maker's formula, 1/f = (μ - 1)(1/R₁ - 1/R₂), where R₁ = 20 cm and R₂ = -40 cm. Solving for μ when f = 20 cm gives μ = 5/3.
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