Question

For the same angle of incidence in media P, Q and R, the angles of refraction are 45°, 35° and 15° respectively. In which medium will the velocity of light be minimum? Give reason.

Answer 1

We know that n = sin i/sin r

For the same angle of incidence i, the refractive index will be maximum for the medium for which 'r ’ is minimum i.e., for the medium R.
Further, we know that n = c/v

Speed of light is faster in rarer medium so, for the medium r, the value of refractive index will be large and speed of the light minimum. The refractive index is small in p medium. Hence p is rarest medium so the speed of light maximum.