Given a slab with refractive index n=1.33 and incident light striking the top horizontal face at angle i.The maximum value of i for which total internal reflection occurs is:

1 answer

n1 sin theta 1 = n2 sin theta 2

1.33 sin theta 1 = 1 sin 90

sin theta = 1/1.33

theta = 48.8 degrees
That is actually the minimum angle for which total internal reflection occurs. Any less than that and it gets through