Question

when light travels from a rarer to a denser medium its speed ..............​

Answer 1

Explanation:

Rarer medium will have refractive index n2 less than refractive index n1 of denser medium. Thus, according to the law speed will increase when travelling from denser to rarer medium i.e. v2 will be greater than v1

Answer 2

Answer:

when light travels from a rarer to a denser medium its speed decreases