Waves & Optics Practice Test
Multiple Choice: Identify the choice that best completes the statement or answers the question.
1. Which portion of the electromagnetic spectrum is used in a television?
a. infrared waves
c. radio waves
b. X rays
d. gamma waves
2. When red light is compared with violet light,
a. both have the same frequency.
c. both travel at the same speed.
b. both have the same wavelength.
d. red light travels faster than violet light.
3. If you know the wavelength of any form of electromagnetic radiation, you can determine its frequency
a. all wavelengths travel at the same speed.
b. the speed of light varies for each form.
c. wavelength and frequency are equal.
d. the speed of light increases as wavelength increases.
4. What is the frequency of infrared light of 1.0  10 m wavelength?
a. 3.0 10
c. 3.0 10 Hz
b. 3.0 10 Hz
d. 3.0 10 Hz
5. When a straight line is drawn perpendicular to a flat mirror at the point where an incoming ray strikes the
mirror’s surface, the angles of incidence and reflection are measured from the normal and
a. the angles of incidence and reflection are equal.
b. the angle of incidence is greater than the angle of reflection.
c. the angle of incidence is less than the angle of reflection.
d. the angle of incidence can be greater than or less than the angle of reflection.
6. If a light ray strikes a flat mirror at an angle of 29 from the normal, the reflected ray will be
a. 29 from the normal.
c. 29 from the mirror’s surface.
b. 27 from the normal.
d. 61 from the normal.
7. Which best describes the image of a concave mirror when the object’s distance from the mirror is less than the
focal-point distance?
a. virtual, upright, and magnification greater than one
b. real, inverted, and magnification less than one
c. virtual, upright, and magnification less than one
d. real, inverted, and magnification greater than one
8. When light passes at an angle to the normal from one material into another material in which its speed is
a. it is bent toward the normal to the surface.
b. it always lies along the normal to the surface.
c. it is unaffected.
d. it is bent away from the normal to the surface.
9. Glasses help to correct vision by
a. refracting
b. reflecting
c. diffusing
d. absorbing
10. Refraction is the bending of a wave disturbance as it passes at an angle from one ____ into another.
a. glass
c. area
b. medium
d. boundary
____ 11. Part of a pencil that is placed in a glass of water appears bent in relation to the part of the pencil that extends
out of the water. What is this phenomenon called?
a. interference
c. diffraction
b. refraction
d. reflection
____ 12. What type of image is formed when rays of light actually intersect?
a. real
c. curved
b. virtual
d. projected
____ 13. In what direction does a focal ray from an object proceed after passing through a converging lens?
a. The ray passes through the focal point, F.
b. The ray passes through the center of the lens.
c. The ray exits the lens parallel to the principal axis.
d. The ray intersects with the center of curvature, C.
The figure above shows the pattern of a double-slit interference experiment. The center of the pattern is
located at E.
____ 14. In the figure above, which fringe represents a second-order minimum?
a. E
c. G
b. F
d. H
____ 15. In the double-slit interference experiment that produced the figure above, the two slits are moved closer.
Which of the following would occur to the pattern shown in the figure?
a. E would shift to the right.
c. F would shift to the right.
b. E would shift to the left.
d. F would shift to the left.
____ 16. The acronym laser stands for light amplification by ____ emission of radiation.
a. similar
c. spontaneous
b. simultaneous
d. stimulated
Free response: Solve the following problems. Show all of your work for credit (including a diagram, equations used and
calculations). Include units in your final answer.
17. A concave mirror with a focal length of 19.9 cm forms a real image at 29.5 cm from the mirror’s surface
along the principal axis. How far is the corresponding object located from the mirror’s surface?
18. A ray of light passes from air into cubic zirconia at an angle of 46.9 to the normal. The angle of refraction is
19.4°. What is the index of refraction of cubic zirconia?
19. An inverted image 3.8 cm in height is formed in back of a lens. The object used to form the image is 0.54 cm
in height. What is the magnification of the image? Is the image real or virtual?
20. The distance between two slits in a double-slit experiment is 3.1  10 m. The first-order bright fringe is
measured on a screen at an angle of 9.6 from the central maximum. What is the wavelength of the light?