Chapter 17: Reflection and Refraction Practice Test
 1. What is the purpose of cladding in an optical fiber?
 a. prevents reflection b. prevents scattering of light c. causes total internal reflection d. reduces refraction
 2. How does light normally travel?
 a. in concentric circles b. in a curved line c. in a straight line d. always toward a dark area
 3. A light ray is traveling through an unknown material when it intersects ethanol (n = 1.36) at an incident angle of 62.0°. If the angle of refraction is 46.4°, what is the index of refraction of the unknown material?
 a. 2.00 b. 0.985 c. 1.66 d. 1.12
 4. A ray of sunlight travels through air and intersects the surface of water at a small incident angle. The ray is __________.
 a. incident b. reflected c. refracted d. pure
 5. If a refracted ray moves away from the normal, the speed of light of the ray in this material is __________ that of the incident ray.
 a. unrelated to b. the same as c. greater than d. less than
 6. Blue light, which is bent more than red light in a prism, has __________.
 a. a faster speed b. a shorter wavelength c. a longer wavelength d. a lower frequency
 7. In relation to a rainbow that you are looking at, where is the Sun?
 a. behind you b. in front of you c. directly overhead d. in the center of the rainbow
 8. Because of refraction, the Sun actually sets __________ we see it disappear.
 a. at the same time as b. hours before c. after d. before
 9. According to Snell's law, light traveling from a vacuum to glass will __________.
 a. travel at the same speed b. slow down c. speed up d. stop completely
 10. What does Snell's law compare?
 a. the density of the materials b. the cosines of the refracted angles c. the reflective nature of materials d. the sines of the refracted angles