Question

why a lightray bends towards normal when going from rarrer medium to denser medium​

Answer 1

Answer:

You saw that light bends toward the normal in this situation, and that the angle in the denser medium will be smaller than the angle in the rarer medium. ... When light travels from a denser medium to a rarer medium, it bends away from the normal, as illustrated to the left. This behavior follows from Snell's Law.