STANDARD Physics Lens Maker's Formula MCQ Question
Double convex lenses are to be manufactured from a glass of refractive index 1.55, with both faces of same radius of curvature. What is the radius of curvature required if the focal length is to be 20 cm?
11 cm
22 cm
7 cm
6 cm
Correct Answer
Detailed Explanation
Using the lens maker's formula, 1/f = (μ - 1)(1/R₁ - 1/R₂), where μ = 1.55 and R₁ = R₂ = R. Solving for R when f = 20 cm gives R = 22 cm.
Found an issue with this question?
Related Questions
More from Optics
More from
What governs the angles of incidence and reflection according to the laws of reflection?
A 2.5 cm tall object is placed 27 cm in front of a concave mirror with a radius of curvature of 36 cm. At what distance from the mirror will the scree...
A double convex lens has radii of curvature R1 = 20 cm and R2 = 30 cm. The refractive index of the lens material is 1.5. What is the focal length of t...