Question

A, B , C and D are four transparent sheets of equal thickness and made of material of refractive indices `mu_(A), mu_(B), mu_(C), and mu_(D)`. If a light ray propagates through them as shown in the figure, compare their refractive indices and also find if any of them have the same refractive index.

Answer 1

Let us represent angles of incidence and angles of refraction in A, B , C , D as `i_(A), i_(B), i_(c), i_(D), r_(A), r_(B), r_(C) and r_(D)`, respectively.
`r_(B) lt i_(A) rArr mu_(B) gt mu_(A)`
`r_(C) gt i_(B) rArr mu_(B) gt mu_(C)`
`r_(C) = r_(A) rArr mu_(C) = mu_(A)`
`r_(D) lti_(c) rArr mu_(D) gt mu_(C)`
`r_(B) lt r_(D) rArr mu_(B) gt mu_(D)`
as such `m_(A) = mu_(C) lt mu_(D) lt mu_(B)`