speed of light in a vacuum
index of refraction = n = -------------------------------------------
speed of light in the medium
n1sin theta1 = n2sin theta2
(Snell's Law)
The greater the index of refraction, the
smaller the angle compared to the normal.
The wave has a smaller angle in A, thus it
must have the larger index of refraction.
Since it has the larger index of refraction,
it has to have the lower speed (top equation).
The Correct Answer is D. |
