Test 1, Form C
1. The spectrum in Slide 1 is
a) an emission-line spectrum
b) an x-ray spectrum
c) a flat spectrum
d) an absorption-line spectrum
e) a blackbody spectrum
2. Who drew the picture in Slide 2?
a) Claudius Ptolemy
b) Galileo Galilei
c) Nicholas Copernicus
d) Tycho Brahe
e) Johannes Kepler
3. The picture displayed in Slide 3 was taken
a) near the equator.
b) near the south pole.
c) near the north pole.
d) at mid-latitudes (such as the United States).
e) no information about earth latitude is contained on the slide.
4. The diagram on the left in Slide 4 shows the portion of the Moon illuminated
by the Sun as the Moon orbits the Earth. Which position corresponds to the
phase of the Moon illustrated by the picture on the right?
a) Position 7
b) Position 3
c) Position 2
d) Position 6
e) Position 4
5. During a lunar eclipse
a) the Earth's shadow falls on the Sun
b) the Moon's shadow falls on the Earth
c) the Sun's shadow falls on the Moon
d) the Earth stops turning
e) the Earth's shadow falls on the Moon
6. The reason we can't see blackbody radiation from other people is
a) the dust in the air scatters the light emitted by our body.
b) the emission lines from our bodies are much stronger than the blackbody emission.
c) the air in the room absorbs the light emitted by our body.
d) the radiation from room temperature objects (like people) emerges mostly in the infrared
region of the spectrum.
e) no reason -- that's how we do see each other.
7. An astronomer speculates that there is a cloud of cold gas in between
us and the star mu ~Sgr. We can test this hypothesis by
a) observing absorption lines in the spectrum of the star.
b) observing emission lines in the spectrum of the star.
c) observing the movement of the star through space.
d) observing the star's blackbody spectrum.
e) observing the scattered blue light in the spectrum of the star.
8. A planet is 1.5 A.U. from the Sun. This means that
a) the planet will never undergo retrograde motion.
b) the planet takes less than a year to go around the Sun.
c) the planet is a superior planet.
d) the planet is in a circular orbit about the Sun.
e) the planet is closer from the Sun than the Earth.
9. What type of photon has the highest frequency?
a) a microwave photon
b) a red photon
c) a radio photon
d) an infrared photon
e) an ultraviolet photon
10. Planets can be distinguished from stars with the unaided eye because
a) planets move in the sky relative to the stars.
b) planets appear much brighter than any star.
c) planets appear much dimmer than any star.
d) planets can be seen during the day.
e) planets differ in color from the stars.
11. The spectrum of the star Deneb shows a strong absorption line at wavelength
6565 A . We know that hydrogen absorbs photons at a wavelength of 6563 A .
If the absorption seen in Deneb is due to hydrogen in the star's atmosphere,
then
a) Deneb must emit mostly in the ultraviolet.
b) Deneb must be moving towards us.
c) Deneb must be moving away from us.
d) Deneb must be rotating.
e) Deneb must be a red star.
12. The Sun's position on the celestial sphere is contantly changing; the
path that it follows is called the ecliptic. About how long
does it take the Sun to complete one "trip" around the ecliptic?
a) 365 days
b) 27 days
c) 24 hours
d) 180 days
e) 23 hours 56 minutes
13. The Sun is always
a) opposite the Moon in the sky.
b) in a zodiac constellation.
c) north of the celestial equator (at least when seen from State College).
d) on the celestial equator.
e) south of the celestial equator (at least when seen from State College).
14. If the Sun were to shrink to one-tenth its size (but keep its same mass),
what would happen to the orbit of the earth?
a) The Sun's smaller gravity would cause the earth's orbit to become highly elliptical.
b) The Sun's greater gravity would cause the earth to crash into the Sun.
c) The Sun's smaller gravity would cause the earth to orbit farther from the Sun.
d) Nothing.
e) The Sun's greater gravity would cause the earth to orbit closer to the Sun.
15. What type of photon has the longest wavelength?
a) a red photon
b) a yellow photon
c) an x-ray photon
d) an infrared photon
e) a gamma-ray photon
16. One reason early scientists resisted putting the Sun in the
center of the Solar System was that
a) Ptolemy's system did a very good job predicting the positions of planets.
b) precession was unknown at the time.
c) retrograde motion hadn't been discovered.
d) there was no evidence for stellar parallax.
e) no one knew the earth was round.
17. The sidereal day (a full rotation of the Earth measured relative to
distant stars) is shorter than a solar day (a full rotation of the
Earth relative to the Sun) because
a) the Earth's axis is precessing.
b) the Earth's axis is tilted with respect to the ecliptic plane.
c) the Earth orbits the Sun.
d) the Moon orbits the Earth.
e) none of the above
18. Ancient astronomers found it difficult to explain the motions of the planets because
a) planets move much faster than the Sun and the Moon
b) the Sun and the Moon always show retrograde motion
c) planets are much fainter than the Sun and the Moon
d) planets sometimes reverse their observed motion in the sky (retrograde motion)
e) none of the above
19. A 4-meter telescope
a) can magnify more than a 2-meter telescope.
b) can see more of the electromagnetic spectrum than a 2-meter telescope.
c) has better ``seeing'' than a 2-meter telescope.
d) has a larger field-of-view than a 2-meter telescope.
e) can see fainter than a 2-meter telescope.
20. The first person to place the Sun in the center of the Solar System was
a) Isaac Newton
b) Johannes Kepler
c) Nicholai Copernicus
d) Galileo Galilei
e) Tycho Brahe
21. Which of these statements about planetary orbits in our solar system
is true?
a) Planets spend more time near their aphelion (furthest point) than perihelion (closest
point).
b) Planets always travel west to east in the sky.
c) The planets move in elliptical orbits with the Sun at the precise center of the ellipse.
d) Inferior planets take more time to go around the Sun than superior planets.
e) Planets are usually found far from the ecliptic plane.
22. The best test of a scientific hypothesis is how
a) easily it is transcribed into mathematical notation
b) simply it explains known observations
c) well it agrees with known theories
d) well it predicts new observations
e) well it explains known observations
23. A solar flare emits light at all wavelengths. Which reaches the
Earth first?
a) the optical light
b) the x-rays
c) the microwave light
d) the radio waves
e) all reach the Earth at the same time
24. Circumpolar constellations
a) can be observed all night.
b) are visible from the equator during the summer.
c) are visible from the equator during the winter.
d) cannot be seen from State College.
e) are also called zodiac constellations.
25. What is the fundamental difference between a reflecting telescope and a
refracting telescope?
a) A reflecting telescope has a longer tube than a refracting telescope.
b) A reflecting telescope has less magnification than a refracting telescope.
c) A reflecting telescope can see fainter stars than a refracting telescope.
d) A reflecting telescope gathers light with a mirror, while a refracting telescope gathers
light with a lens.
e) A reflecting telescope has a larger field-of-view than a refracting telescope.
26. Imagine a planet whose rotation axis is perpendicular to its orbital plane. How would you describe the its seasons?
a) longer than those on Earth.
b) constant -- there would be no seasons.
c) the same as those on Earth.
d) shorter than those on Earth.
e) more intense than those on Earth.
27. The setting sun is red because
a) the gases in the Earth's atmosphere absorb most of the blue light.
b) dust scatters much of the Sun's blue light away from us.
c) the air near the horizon is reddish.
d) the ozone layer absorbs all the Sun's ultraviolet light.
e) the Sun emits most of its light in the red region of the spectrum.
28. Solar eclipses only occur
a) during a Full Moon.
b) during a New Moon.
c) during the solstice.
d) during a high tide.
e) during a neap tide.
29. Kepler's second law (equal areas in equal times) says in effect that
a) planets move at a steady pace around the Sun
b) more distant planets must orbit faster, to sweep out the same area in a similar time
c) planets move slower as they near the Sun
d) planets move faster as they near the Sun
e) none of the above
30. A 10-pound iron ball which is 5-inches in diameter is heated to
6000 K. A 20-pound lead ball which is also 5-inches in diameter
is heated to 3000 K. According to what we know about light
a) the iron ball will glow dimmer and appear redder than the lead ball.
b) the iron ball will glow dimmer and appear bluer than the lead ball.
c) the iron ball will glow brighter and appear bluer than the lead ball.
d) the iron ball will glow brighter and appear redder than the lead ball.
e) the light emitted from both balls will be identical.
31. The fundamental reason why the Earth has seasons is that
a) the Earth's axis is tilted with respect to the ecliptic plane.
b) the Earth is going around the Sun.
c) the Earth is in the center of the celestial sphere.
d) the Earth's axis is precessing.
e) the Earth is spinning on its axis.
32. When Venus is in opposition (opposite the Sun), it
a) is closest to the Sun in its orbit.
b) is furthest from the Sun in its orbit.
c) appears to be moving backward against the background of stars.
d) is visible near midnight.
e) none of the above --- Venus is never seen in opposition!
33. The circular shape of the Earth's shadow on the Moon led
early astronomers to conclude that
a) the Moon must orbit the Sun
b) the Earth must be at rest
c) the Moon is a sphere
d) the Earth is at the center of the Solar System
e) the Earth is a sphere
34. Which did Galileo not observe?
a) the moons of Jupiter.
b) the phases of Venus.
c) the parallax of stars.
d) the mountains of the Moon.
e) the rings of Saturn.
35. Pluto, which is in the outer part of our solar system, is 38 Astronomical
Units from the Sun. Consider an object at 76 Astronomical Units from the
Sun. The Sun's gravitational attraction on this object
a) would be just as strong as it is on the Earth.
b) would be much greater than it is on the Earth.
c) would depend on the composition of the object.
d) would be much less than it is on the Earth.
e) would be zero -- the object would be outside the gravitational influence of the Sun.
36. What causes light from a star to be Doppler-shifted?
a) the speed of the star toward or away from us.
b) temperature differences between us and the star.
c) the distance between us and the star.
d) the gas and dust between us and the star.
e) none of the above.
37. During a full moon, how much of the total Moon's surface is being illuminated by the Sun?
a) half
b) more than half
c) none
d) less than half
e) all
38. X-ray radiation from astronomical objects is best studied
a) from airplanes.
b) during the day.
c) from mountaintops.
d) from space.
e) from the desert.
39. Two stars have the same size and have the same temperature, but one
is twice as far away as the other. The more distant star
a) will appear four times dimmer and much redder than the nearer star.
b) will appear twice as dim and much redder than the nearer star.
c) will appear identical to the nearer star.
d) will appear twice as dim and much bluer than the nearer star.
e) will appear four times dimmer than the nearer star.
40. Which type of photon carries the most energy?
a) a blue photon
b) an ultraviolet photon
c) an infrared photon
d) a microwave photon
e) an x-ray photon
41. On December 21, the Sun will set
a) in the northeast
b) in the southwest
c) in the southeast
d) due west
e) in the northwest
42. Atoms have particular associated spectral lines because
a) light waves can show the Doppler effect.
b) the speed of light is constant.
c) electrons only have certain allowed orbits.
d) photons have only certain allowed orbits.
e) light consists of waves.
43. A mountaintop is a good location for optical telescopes because the site is
a) closer to astronomical objects.
b) above much of the atmosphere.
c) colder than the valleys.
d) cheaper to build on than in cities.
e) all of the above.
44. We see a full moon rise at
a) sunrise
b) sunset
c) midnight
d) around 9 p.m.
e) noon
45. The time it takes for one celestial body to orbit another
a) depends only on the semi-major axis of the orbit.
b) depends on the masses of the two bodies and the ellipticity of the orbit.
c) depends on the masses of the two bodies and the focus of the ellipse.
d) depends on the masses of the two bodies and the semi-major axis of the orbit.
e) depends only on the masses of the two bodies.
46. We see different constellations in the summer than in the winter because
a) the Earth is round.
b) the direction of the earth's axis precesses.
c) the Earth goes around the Sun.
d) the stars have parallax.
e) the planets occasionally undergo retrograde motion.
47. In the Bohr model of the atom
a) electrons cannot leave the atom.
b) protons can be at any distance from the nucleus.
c) electrons can only orbit at certain fixed distances from the nucleus.
d) electrons can orbit at any distance from the nucleus.
e) electrons cannot interact with light.
48. We experience extra high tides (spring tides) during
a) new moon
b) full moon
c) first quarter moon
d) third quarter moon
e) both full and new moon
49. In 10,000 years,
a) Polaris will no longer be the north star.
b) Orion and Scorpius will no longer be opposite each other on the sky.
c) the Moon will no longer cause eclipses.
d) a sidereal day will no longer be shorter than a solar day.
e) the Earth will no longer have seasons.
50. Which type of light can be observed from the ground?
a) gamma-rays
b) radio waves
c) ultraviolet light
d) x-rays
e) none of the above can be observed from the ground.