Question

Circular angle for light moving from medium 1 to medium 2 is ∅. The speed of light in medium 1 is v. then speed in medium 2 is

Answer 1

cosine(angle)=refrective index=speed of light in the first medium/speed of light in the second medium

Answer 2

Let n1 be the refractive index of first medium.
Let n2 be the refractive index of second medium.
Critical angle =θ
speed of light in first medium=V
speed of light in second medium is =? V2
relation between critical angle and refractive index.
Sinθ=n2/n1-----------(1)
relation between refractive index and speed
n2/n1=v1/v2
n2/n1=V/V2----------------(2)
equating equation 1 and 2
sinθ=V/V2
V2=V/Sinθ
∴speed in second medium is V/Sinθ