The critical angle for light going from medium ‘x’ to medium ‘y’ is ' θ ' . The speed of light in medium ‘x’ is ' v x ' . The speed of light in medium ‘y’ is

Step-by-step solution

The critical angle is that angle on incidence in the denser medium for which the angle of refraction in rarer medium is 90 o , i . e . s i n θ s i n 90 o = μ y μ x ⇒ s i n θ = μ y μ x …. (i) Where, μ = refractive index of medium. A l s o , μ = s p e e d o f l i g h t i n v a c u u m s p e e d o f l i g h t i n m e d i u m = c v … (ii) Form Eqs. (i) and (ii), we get s i n θ c v y × v x c = v x v y ⇒ v y = v x s i n θ