Question

for the same value of angle of incidence and the angle of refraction in 3 medium A B and C are 15 degree 25 degree and 35 degree respectively in the which medium would the velocity of light be minimum?

Answer 1

in the medium A which form 15°angle.
since medium A <medium B< medium C
therefore 15°<25°<35°
so,the minimum velocity in light is in medium A as it forms less angle.
hope it's the required answer....

Answer 2

As per question, i = r

This implies -> sin(i) = sin(r)

Then from the Snell's Law;

μ = $\frac{sin(i)}{sin(r)}$

i.e Refractive index of the 2nd medium with respect to the 1st medium is the ratio of sine of the angle of incidence and angle of refraction.

So, refractive index of the 2nd medium is same as that for the 1st medium.

And hence, light will not be refracted, which does not have any impact on velocity of light.