For the same angle of incidence, the angle of refraction in three different media A, B and C 10°, 25° and 40°, respectively. In which medium the velocity of light will be maximum?
Refractive index (μ) = 
……(1)
Hence refractive index of a medium is inversely proportional to the speed of light in that medium.
Also μ = 
…………….. (2)
⇒ Refractive index is inversely proportional to the angle of refraction.
From (1) and (2)
Velocity of light is directly proportional to the angle of refraction.
Thus velocity of light is maximum in medium C because angle of refraction is 400 is maximum.
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