Please answer me

Let n1, n2 be the refractive indices of the two mediums, and

n1 sin i = n2 sin r .........Snell's law,

For normal incidence, i = 0.

sin i = 0.

Hence sin r = 0

r = 0.

As we can see the light ray passes undeviated into 2nd medium.

regards,

Team,

TopperLearning.