A plano-convex lens of refractive index μ 1 and focal length f 1 is kept in contact with another plano-concave lens of refractive index μ 2 and focal length f 2 . If the radius of curvature of their spherical faces is R each and f 1 = 2 f 2 , the μ 1 and μ 2 are related as:

Step-by-step solution

Given, f 1 = 2 f 2 Lens maker formula for the first lens is given by, 1 f 1 = μ 1 - 1 1 R - 1 ∞             ...( 1 ) Lens maker formula for the second lens is given by, 1 f 2 = μ 2 - 1 1 R - 1 ∞             ...( 2 ) After 1 2 , we get: f 2 f 1 = μ 1 - 1 μ 2 - 1 = 1 2 ⇒ 2 μ 1 - 2 = μ 2 - 1 ⇒ 2 μ 1 - μ 2 = 1