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COMEDK · Physics · 25. Ray Optics

A ray of light is travelling from glass of refractive index \(\dfrac{3}{2}\) to water of refractive index \(\dfrac{4}{3}\). What is the minimum angle of incidence for which no light enters in to the water?

  1. A \(i_c=\sin ^{-1}\left(\dfrac{9}{8}\right)\)
  2. B \(i_c=\sin ^{-1}\left(\dfrac{1}{2}\right)\)
  3. C \(i_c=\sin ^{-1}\left(\dfrac{2}{3}\right)\)
  4. D \(i_c=\sin ^{-1}\left(\dfrac{8}{9}\right)\)
Verified Solution

Answer & Solution

Correct Answer

(D) \(i_c=\sin ^{-1}\left(\dfrac{8}{9}\right)\)

Step-by-step Solution

Detailed explanation

The condition for no light to enter the water is that the angle of incidence must be greater than or equal to the critical angle \(i_c\). The critical angle \(i_c\) is defined by the relation \(\sin(i_c) = \dfrac{\mu_{rarer}}{\mu_{denser}}\). Given the refractive index of glass…