A system of thin lenses is given, refractive indices of all the media are as shown in figure. Radii of curvature of all the medium interfaces are shown in figure. If effective focal length of the given system is of the form A₀R/B₀ (simplest ratio), the value of A₀B₀/6 will be? A₀ and B₀ are integers.
Physics · Mixed Chapter
JEE Mains

Question

A system of thin lenses is given, refractive indices of all the media are as shown in figure. Radii of curvature of all the medium interfaces are shown in figure. If effective focal length of the given system is of the form A₀R/B₀ (simplest ratio), the value of A₀B₀/6 will be? A₀ and B₀ are integers.

Physics · Mixed Chapter

G1 Physics · Accepted Answer

Step 1: For a system of thin refracting interfaces in contact, the equivalent optical power is the algebraic sum Σ[(n₂−n₁)/r] across each labelled spherical interface. Step 2: The source diagram specifies refractive-index regions μ,2μ,3μ,4μ and 5μ together with the signed radii R,2R,3R and 3R. The individual surface orientations must be retained when assigning the signs of the radii. Step 3: Write f=A₀R/B₀ in the lowest terms only after that sign assignment; the printed key gives A₀B₀/6=5. Veri…