Physics 3050G
Excursions in Physics
Fourth Hour Exam
April 30, 2003
Enter all your answers in the “Scantron sheet” or the “bubble sheet” or the “answer sheet”. Turn in only that sheet. Anything you write on this exam will not be seen or used or considered or graded. Be sure your name is on the “bubble sheet” you hand in. Be sure your name is bubbled-in. Be sure your answers are recorded correctly. Please put the date on the sheet as well.
For every question, also consider the following as a possible answer:
E) none of the above
For every question, also consider the following as a possible answer:
e) none of the above
1. Electromagnetic waves consist of
a) compressions and rarefactions of electromagnetic pulses.
b) oscillating electric and magnetic fields.
c) particles of light energy.
d) high-frequency gravitational waves.
2. Electromagnetic waves
a) can travel through a vacuum.
b) need a medium to travel through.
3. The main difference between a radio wave and a light wave is its
a) speed
b) wavelength
c) EM characteristic
d) all of the above
4. Which of these electromagnetic waves has the shortest wavelength?
a) X-rays
b) ultraviolet waves
c) infrared waves
d) radio waves
5. Compared to ultraviolet waves, the wavelength of infrared is
a) longer
b) identical
c) shorter
6. Compared to radio waves, the velocity of visible light waves in a
vacuum is
a) greater
b) the same
c) less
7. Compared to radio waves, the wavelength of visible light waves in
a vacuum is
a) longer
b) the same
c) shorter
8. Which of the following is fundamentally different from the others?
a) X-rays
b) visible light waves
c) sound waves
d) radio waves
9. The sensation of color is seen when light falls on the eye's
a) rods
b) cones
c) cornea
d) crystalline lens
10. The cones in the retina of the eye are
a) most densely packed at the center of vision, the fovea.
b) uniformly spread along the visual field.
c) concentrated along the periphery of vision.
d) concentrated at the “blind spot” where the optic nerve attaches
to the retina.
11. If a light signal and a radio signal were emitted simultaneously
from Alpha Centauri, the star closest to Earth, the first signal to reach
Earth would be the
a) the radio signal.
b) the light signal.
c) both would arrive at the same time
12. Color depends on what characteristic of light?
a) wavelength
b) frequency
c) both of these
d) neither of these
13. The colored dots that make up the color on a TV screen are
a) red, yellow, green.
b) red, yellow, blue.
c) red, green, blue.
d) cyan, magenta, yellow.
14. Magenta light is a mixture of
a) red and yellow.
b) cyan and yellow.
c) red and blue.
d) yellow and blue.
15. Colors seen on TV result from color
a) subtraction.
b) addition.
c) neither of these.
d) either of these.
16. Colors made by an ink jet printer result from color
a) subtraction.
b) addition.
c) neither of these.
d) either of these.
17. Different colors of light correspond to different light
a) velocities.
b) intensities.
c) polarities.
d) wavelengths.
18. Look at a full-color picture in a magazine with a magnifying glass
and you'll see that the inks used are
a) red, green, cyan, and blue.
b) red, green, blue, and black.
c) magenta, cyan, yellow, and black.
d) magenta, cyan, yellow, and blue.
19. A sheet of red paper will look black (or dark grey) when illuminated
with
a) red light.
b) cyan light.
c) yellow light.
d) magenta light.
20. A blue object will appear black (or dark grey) when illuminated with
a) blue light
b) yellow light
c) magenta light
d) cyan light
21. A mixture of red and green light produces
a) blue.
b) magenta.
c) yellow.
d) cyan.
22. A spotlight produces white light which then passes through a filter
that absorbs the red light. What color is the light that passes through?
a) red.
b) yellow.
c) magenta.
d) cyan.
23. Light travels fastest in
a) water.
b) vacuum.
c) air.
d) steel.
24. Refraction, as light goes from air to glass, results from differences
in light's
a) frequency in air and glass.
b) incident angle.
c) speed in air and glass.
d) all of the above.
25. Light refracts when traveling from glass into air because light
a) intensity is greater in air than in glass.
b) frequency is greater in glass than in air.
c) speed is greater in air than in glass.
d) polarization is greater in glass than in air.
26. A beam of light emerges from glass into air at an angle. The beam
is bent
a) toward the normal (or perpendicular).
b) away from the normal (or perpendicular)
c) at an angle of 49° .
d) only if it is polarized.
27. When a light beam emerges from water into air, the light speed
a) increases.
b) remains the same.
c) decreases.
28. Refraction causes the bottom of a swimming pool to appear
a) farther away than it really is.
b) closer to the surface than it really is.
29. Different colors are dispersed by a prism because different colors
in the prism have different
a) speeds.
b) angles of incidence.
c) energies.
d) momenta.
30. The critical angle for a transparent material is the angle at and
beyond which all light within the material is totally
a) absorbed.
b) reflected.
c) refracted.
d) polarized.
31. In an optical fiber, light actually
a) curves in a direction parallel to the central axis of the fiber.
b) travels in straight-line segments.
c) travels along the outer surface of the fiber.
d) all of the above.
32. Your image in a plane mirror is
a) virtual.
b) real.
c) both of these.
d) inverted
33. The type of lens that spreads parallel light is a
a) converging lens.
b) diverging lens.
c) either of these.
34. Which of the following can be projected onto a viewing screen?
a) a virtual image.
b) a real image.
c) a convex image.
d) a concave image.
35. The image of something “infinitely far away”, like the
Sun, produced by a converging lens appears
a) between the lens and the focal point.
b) at the focal point.
c) between the focal point and twice the focal length.
d) at twice the focal length.
36. According to Huygens' principle, every point on a wave
a) is a diffraction source.
b) behaves as a source of new waves.
c) is the superposition of every other part of the wave.
d) all of the above.
37. Consider plane waves incident upon a barrier with a small opening.
After passing through the opening, the waves
a) continue as plane waves.
b) spread out.
c) are polarized.
d) converge.
38. Light will not pass through a pair of Polaroids when their axes are
a) parallel.
b) rotated 45°.
c) rotated 57°.
d) perpendicular.
39. Light from a laser is
a) monochromatic.
b) in phase.
c) coherent.
d) all of the above.
40. A 2-m tall person viewing his full-length image in a plane mirror
requires a mirror that is at least
a) 0.5 m
b) 1.0 m.
c) 2.0 m.
d) This depends upon how far the person is from the mirror.
41. In the interference pattern produced by shining a laser through two
slits (Young’s double slit experiment), the dark areas are the result
of
a) destructive interference.
b) polarization.
c) constructive interference.
d) restructive construction.
42. When light passes through a diffraction grating it is bent. Light
with a greater wavelength will be bent
a) through a smaller angle.
b) the same (bending is independent of wavelength).
c) through a larger angle.
43. Rainbows are a result of
a) dispersion and reflection.
b) dispersion and polarization.
c) reconstruction and polarization.
d) constructive and destructive interference.
44. Secondary (or double) rainbows are a result of
a) one refraction and one reflection.
b) one refraction and two reflections.
c) two refractions and one reflection.
d) twp refractions and two reflections.
45. Consider two perpendicular polarizing filters, A and B, as shown below. Another polarizing filter, C, is placed between them. As this third polarizing filter C is rotated through a full 360°, how many times does the beam of light cycle from dark to bright?
a) only once.
b) twice.
c) four times.
d) eight times.
46. An object is placed 20 cm from a converging lens that has a focal length of 10 cm. Make a ray diagram of this situation. From the ray diagram, characterize the image.
The image is
a) real, and inverted.
b) virtual, inverted, and smaller.
c) virtual, upright, and smaller.
d) virtual, inverted, and larger.
47. An object is placed 30 cm from a converging lens that has a focal
length of 10 cm. Make a ray diagram of this situation. From the ray diagram,
characterize the image.
The image is
a) real, inverted, and larger.
b) real, inverted, and smaller.
c) virtual, upright, and smaller.
d) virtual, inverted, and smaller.
48. An object is placed 15 cm from a converging lens that has a focal
length of 10 cm. Make a ray diagram of this situation. From the ray diagram,
characterize the image.
The image is
a) real, inverted, and larger.
b) real, inverted, and smaller.
c) real, upright, and smaller.
d) virtual, upright, and larger.
49. An object is placed 30 cm from a diverging lens that has a focal
length of - 10 cm. Make a ray diagram of this situation. From the
ray diagram, characterize the image.
The image is
A) real, inverted, and larger.
B) real, inverted, and smaller.
C) virtual, upright, and smaller.
D) virtual, inverted, and smaller.
50. An object is placed 20 cm from a concave mirror that has a focal
length of + 30 cm. Make a ray diagram of this situation. From the
ray diagram, characterize the image.
The image is
A) real, inverted, and larger.
B) real, inverted, and smaller.
C) virtual, upright, and larger.
D) virtual, inverted, and smaller.