For the same value of angle incidence, the angles of refraction in three media A, B and C are 15°, 25° and 35° respectively. In which medium would the velocity of light be minimum?

Solution

As per Snell’s law we have,
$straight n space equals space fraction numerator sin space straight i over denominator sin space straight r end fraction space equals space straight c over straight v$
For given i, v $proportional to$ sin r
r is minimum in medium A, so velocity of light is minimum in medium A.