Concepts Of Physics MCQ Edition [Volume 1]PhysicsGeometrical Optics
A stack of k transparent slabs is arranged one on top of another, having refractive indices ₁, ₂, ₃, , _k and respective thicknesses t₁, t₂, t₃, , t_k . If an object is viewed through this assembly using nearly perpendicular light, determine the equivalent refractive index of the system that would cause the image to form at the identical location.
Options
- A_ i=1 ^ k _i t_i _ i=1 ^ k t_i
- B_ i=1 ^ k t_i _ i=1 ^ k (t_i / _i)
- C_ i=1 ^ k (t_i / _i) _ i=1 ^ k t_i
- D_ i=1 ^ k t_i _ i=1 ^ k _i t_i
Correct answer
B. _ i=1 ^ k t_i _ i=1 ^ k (t_i / _i)
Step-by-step solution
The apparent depth of an object viewed through a single slab of thickness t and refractive index is given by t . For a stack of k slabs, the total apparent depth is the sum of the individual apparent depths: Apparent depth = _ i=1 ^ k t_i _i If the entire assembly is replaced by a single equivalent slab of total thickness _ i=1 ^ k t_i and equivalent refractive index _ eq , its apparent depth would be: Equivalent apparent depth = _ i=1 ^ k t_i _ eq For the image to form at the identical location, the total apparent