Physics
posted by Samantha on .
Light travels in a line of optical fiber by total internal reflection between a core of refractive index 1.48 and a cladding 1.46 refractive index.
The critical angle for total internal reflection to occur inside the core of the fiber is ...
80.6º
48.8º
43.2º
42.5º
24.4º
I keep getting this one wrong too. Please help

For critical reflection, the angle of refraction in the less dense medium is 90 degrees.
Snell's Law says that, in this case,
1.46 sin 90 = 1.46 = 1.48 sin theta
theta = sin^1 1.46/1.48 = sin^1 0.9865
Look up the angle. It is one of your choices. 
inverse sin> =
Sin^1(1.461.48)= 80.57 deg
9080.57 = The Max_ang = 9.43 deg 
inverse sin> =
Sin^1(1.461.48)= 80.57 deg
9080.57 = The Max_ang = 9.43 deg