For the same value of angle of incidence the angle of refraction in three media A,Band C are 15 degree,25 degree and 35 degree respectively.in which medium the velocity of light be minimum?
We know that velocity of light in amedium is inversely proportional to the refractive index of the medium from the equation
n = c / v .............(1)
Moreover the refractive index of the medium is inversely proportional to the angle of refraction for the same angle of incidence from the equation
n = sin i / sin r ..............(2)
From (1) and (2) ,it is clear that velociy of light in a medium is directly proportional to the angle of refraction in that medium at a particular angle of incidence.
Thus the velocity of light is minimum in medium A where the angle of refraction is minimum.