For the same angle of incidence, the angles of refraction in media `P, Q and R` are `35^(@) ,25^(@), 15^(@)` resp. In which medium will the velocity of light be minimum ?

Explanation

For medium `R`, angle of refraction (r ) is minimum. Therefore, `mu = (sin i)/(sin r)` is maximum. As `mu =( c)/(v)`, therefore, `v` is minimum, i.e., velocity of light is minimum in medium `R`.