Comins DEU 3e Ch 03 Quiz 1 completed
The correct answers are written in bold, italic and underlined.
The most important questions to study for the exam are highlighted.
1. Violet light differs from red light in that
• violet light has a longer wavelength than red light.
• violet light has a shorter wavelength than red light.
• violet light travels more slowly (through a vacuum) than red light.
2. In 1801, Thomas Young performed a crucial experiment on the nature of light when he
• demonstrated that white light was made up of colors that could be split by a prism and
that these colors were not produced by the glass through which the light passed.
• demonstrated the wave nature of light by passing light through two slits and
obtaining a pattern of bright and dark bands on a screen that he correctly
interpreted as interference between the two light beams.
• proved mathematically that light could be described by oscillating electric and
magnetic fields.
3. In Roemer's observations of Jupiter and the timing of the orbits of its moons, how
much farther did light have to travel from Jupiter to the Earth when Jupiter was at a
position of conjunction than when it was at opposition?
• 1 AU
• No farther because Jupiter's distance from the Earth does not vary
• 2 AU
4. If the speed of sound is about 333 meters per second and the speed of light is 3 x 108
meters per second, what will be the delay between seeing the flash of lightning and
hearing the thunder from a storm 1 km away?
• There will be virtually no delay because both light and sound travel very fast, the
delay being a very small fraction of a second.
• 3 seconds
• 0.33 seconds
5. What is different about light compared to other waves such as sound waves or waves
on water?
• If we measure the speed of light, we always get the same value, regardless of how
we or the light source are moving.
• If a source of light is moving relative to us, the light waves emitted in the direction of
motion of the source move faster than if the source were at rest, increasing the
observed wavelength of the waves.
• If light passes through two closely spaced openings, the waves leaving the openings
spread out and interfere with each other.
6. Suppose a light source is emitting red light of 700-nm wavelength and another light
source is emitting ultraviolet light of 350-nm wavelength. Each photon of the ultraviolet
light has
• half the energy of each photon of the red light.
• either more OR less energy than each photon of the red light, depending on the
intensities of the two light sources.
• twice the energy of each photon of the red light.
7. The ratio of the energy of a photon of X rays with a wavelength of 0.05 nm to that of a
photon of visible light of wavelength 500 nm is
• 10,000.
• 1 because photons of electromagnetic radiation all have the same energy, but more
photons per second are emitted by an X-ray source than by a visible light source.
• 1/10,000.
8. The photoelectric effect is
• the darkening of certain types of glass when exposed to sunlight.
• the emission of electrons from a metal surface when it is illuminated by light.
• the change in the speed of light when it enters a dense transparent material such as
glass, caused by the electric fields between atoms.
9. The person who first showed that light travels in wave packets, or photons, in which
the energy of a photon depends on its wavelength, was
• James Clerk Maxwell.
• Albert Einstein.
• Thomas Young.
10. Electromagnetic radiation
• is limited to wavelengths shorter than radio waves of about 1 m in length.
• is limited to wavelengths near those of visible light, from ultraviolet to infrared
radiation. All other radiations outside this range (e.g., X rays, radio) are NOT true
electromagnetic radiations.
• has no wavelength limits, either long or short.
11. Which of the following types of electromagnetic radiation from space are completely
blocked by the Earth's atmosphere and therefore do not reach the Earth's surface?
• Infrared radiation
• Radio waves
• Gamma rays
12. The one distinguishing difference between X rays and visible light is that
• the speed of X rays is higher than that of visible light because X-ray photons possess
more energy than light photons.
•
•
the wavelength of X rays is higher than that of visible light, leading to the higher
penetrating power of X rays through solid matter.
the photon energy of X rays is higher than that of visible light.
13. The type of telescope that uses a parabolic primary mirror and a plane (or flat)
secondary mirror that reflects light at right angles to the incoming beam is known as a
• refracting telescope.
• Newtonian telescope.
• Cassegrain telescope.
14. The most important purpose of a large ground-based telescope is to
• collect more light from distant objects.
• produce magnified images of distant objects.
• produce sharper images than smaller telescopes.
15. How much more light will be collected by the new Galileo telescope on Hawaii,
equipped with an 8-m diameter mirror, than by the great Hale telescope on Mt. Palomar
in California with a 5-m diameter primary mirror?
• 1.6 times
• 2.56 times
• 3.2 times
16. When the focal length of the eyepiece of a refracting telescope is reduced, the overall
magnification of the telescope
• is decreased.
• is increased.
• remains the same because telescope magnification does not depend on the eyepiece.
17. A person has a telescope with a primary mirror with a diameter of 0.3 m and a focal
length of 1.2 m fitted with an eyepiece with a diameter of 10.0 mm and focal length of
8.0 mm. What is the magnifying power of this telescope?
• 4
• 150
• 30
18. The main reason an electronic CCD camera is more capable than the human eye at
detecting fainter objects through telescopes is that
• the CCD is able to store and integrate light for a long period, whereas the eye clears
the images several times a second.
• the CCD is capable of much higher resolution than the eye is, by concentrating light
into smaller images.
• the CCD is sensitive to a wider range of colors than the eye is.
19. After passing from the vacuum of space through a piece of glass and then passing
back into the vacuum, photons of light will be traveling
•
•
•
faster than before they entered the glass, having been accelerated by their passage
through the glass.
at the same speed as before they entered the glass.
slower than before they entered the glass because they will have been slowed down
by their passage through the glass.
20. A flash of light is transmitted simultaneously through two parallel tubes of length 1
km, the first one evacuated, the second one filled with water. Detectors sense the arrival
times of the light flash at the ends of these tubes. What will be the relationship between
arrival times of these light flashes?
• The flashes of light will arrive simultaneously at the ends of the tubes because light
always travels at the same speed.
• The flash will arrive earlier through the water-filled tube.
• The flash will arrive earlier through the evacuated tube.