Question

A thin convex lens is made of two materials with refractive indices n₁ and n₂, as
shown in figure. The radius of curvature of the left and right spherical surfaces
are equal. ???? is the focal length of the lens when n₁ = n₂ = n. The focal length is ???? +
∆???? when n₁ = n and n₂ = n + ∆n. Assuming ∆n << (n – 1) and 1 < n < 2. The correct statement(s) is/are.
| ∆???? | | ∆n |
A. | ???? | < | n |

B. If ∆n < 0 then ∆f > 0
n f
C. For n = 1.5, ∆n= 10⁻³ and f = 20 cm, the value of |∆f| will be 0.02 cm (round off to 2nd decimal place).
D. The relation between ∆f /f and ∆n/n remains unchanged if both the convex surfaces are replaced by concave surfaces of the same radius of curvature.

Answer 1

Answer:

n3 n550cn3 444444....