Question

why frequency remains unaltered but wavelength and speed of light changes due to refraction?​

Answer 1

Answer:

Wave speed, frequency and wavelength in refraction

Although the wave slows down, its frequency remains the same, due to the fact that its wavelength is shorter. When waves travel from one medium to another the frequency never changes. As waves travel into the denser medium, they slow down and wavelength decreases.

Answer 2

• Only wavelength and velocity changes depending upon the medium by the relation

$\huge\bold\red{ => }$ $\fbox\green{ v \: = \: fλ }$

• but frequency remains unchanged.