Engineering
Physics
Plane Surface Refraction
Question

A transparent slab of thickness d has a refractive index n(z) that increases with z. Here z is the vertical distance inside the slab, measured from the top. The slab is placed between two media with uniform refractive indices n1 and n2 (>n1), as shown in the figure. A ray of light is incident with angle qi from medium 1 and emerges in medium 2 with refraction angle θf with a lateral displacement ℓ.

Which of the following statement(s) is(are) true ?

ℓ is independent of n2

n1 sin θi = n2 sin θf

ℓ is dependent on n(z)

n1 sin θi = (n2 – n1) sin θf

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Solution

By snell's law

⇒ sin θisin θF=n2n1

also ⇒ for refraction till the n (z),

⇒ here μ of this medium increases, simultaneosuly, the emergent ray is always depend on the refractive index of medium n (z) (here) also 'ℓ ' depends on the refractive index of the medium here n(z) and this ℓ is clearly independent of medium n2.