Study Questions - Set 1
Chapters 1-2
1. A scientist observes a new phenomenon that disagrees with the scientist's own explanation or hypothesis. Following the scientific method, the correct procedure is to
A.accept the disagreement as part of the fundamental incomprehensibility of the universe.
B.modify the hypothesis.
C.wait until someone develops an adequate explanation before announcing the new observation.
D.discard the observation as erroneous.


2. In following the principles of the scientific method, a theory proposed to explain a given phenomenon must
A.explain all previous and reliable observations in a consistent manner but need not suggest new tests for the theory since a theory should be complete in itself.
B.explain all known and reliable observations and predict new experiments and observations.
C.agree with and build on previous theories but need not explain all observations since some of these may be erroneous.
D.predict new and different experiments that will extend the scope of the theoretical understanding but need not explain all the previous observations since no theory is expected to explain everything completely.


3. The idea of thermonuclear fusion, the release of energy following the conversion of hydrogen nuclei into a helium nucleus, was first suggested as the source of energy in
A.the interior of Earth.
B.the central core of the Sun.
C.a weapon of mass destruction.
D.a controllable nuclear power station.


4. One astronomical unit, or one AU is defined as the
A.distance traveled by light in one year.
B.mean distance between the Sun and the Earth.
C.distance from which Earth-Sun distance will subtend an angle of one arcsecond.
D.distance traveled by light in one second.


5. One light-year is the
A.distance that light travels in one year.
B.time taken for the Earth to orbit the Sun once.
C.distance between Earth and Sun.
D.time taken for light to travel from the Sun to the Earth.


6. What is the distance between Earth and the nearest star? (THINK carefully about your answer!) (Check the list of stars in the Appendix 4 of Freedman and Kaufmann, Universe, 6th ed.)
A.5.2 AU
B.4.3 parsecs
C.1 AU
D.4.3 light-years


7. Suppose that at the same time on the same night we see one supernova (a star exploding) in the Andromeda galaxy, 2 million light-years away from us, and another in the galaxy M82, 6 million light-years away from us. Which of the following statements is correct?
A.Both stars exploded at the same time, because we saw the explosions at the same time.
B.We cannot tell which star actually exploded first, because they are so far away.
C.The supernova in the Andromeda galaxy actually occurred after the one in M82.
D.The supernova in the Andromeda galaxy actually occurred before the one in M82.


8. In modern astronomy, the constellations are
A.clusters of stars that are held together by the mutual gravitational attractions of the individual stars in the cluster.
B.nearby galaxies to which astronomers have given specific names.
C.12 regions of sky through which the Sun, Moon, and planets move as seen from the Earth.
D.88 regions of sky, covering the entire sky.


9. Which of the following statements correctly describes the relationship between stars and constellations?
A.Only those stars that were visible to the ancient Greeks are located in constellations.
B.Only the brighter stars are in constellations.
C.Only stars within the zodiac close to the ecliptic, the Earth's orbital plane, are located in constellations.
D.Every star is located in a constellation.


10. The constellation whose stars are used as pointers to the north celestial pole in the northern hemisphere is
A.Leo, the lion, containing the bright star Regulus.
B.Ursa Major, the Big Dipper.
C.Ursa Minor, the Little Bear, containing the bright star Polaris.
D.Bootes, the shepherd, containing the bright star Arcturus.


11. Diurnal motion of objects in the sky is caused by the
A.precession of the Earth's axis.
B.revolution of Earth around the Sun.
C.motion of the Moon across the sky.
D.rotation of the Earth on its axis.


12. What basic pattern do stars seem to trace out in our sky if you watch (or photograph) stars near the north celestial pole for a period of several hours?
A.circles, with the north celestial pole at the center
B.spirals, as the stars move while the Earth rotates
C.almost straight lines, rising from the horizon towards the zenith
D.ellipses, with the north pole at one focus


13. With respect to the stars, the rotation of the Earth carries you toward the
A.south.
B.east.
C.west.
D.north.


14. The celestial equator is defined as the
A.line in the sky that is perpendicular to the Earth's spin axis.
B.line traced in our sky by the Moon each month against the background stars.
C.line traced in our sky by the Sun over one year against the background stars.
D.band of constellations through which the Sun and Moon move in our sky.


15. Which of the following lines or points is always directly over your head, no matter where on the Earth you go?
A.zenith
B.celestial equator
C.ecliptic
D.90° north declination


16. The angle between an observer's horizon and the north celestial pole is governed by
A.latitude.
B.local time.
C.sidereal time.
D.longitude.


17. The two angles used by astronomers to define the position of a star in the sky and define a coordinate system applicable anywhere on Earth are
A.azimuth and elevation.
B.latitude and longitude.
C.horizontal and vertical angles.
D.right ascension and declination.


18. The declination of a star in our sky is defined as the angle between the
A.Sun and the star, measured along the ecliptic.
B.celestial equator and the star, measured along a great circle passing through both celestial poles.
C.center of the galaxy and the star, measured along the galactic equator.
D.

vernal equinox and the star, measured along the celestial equator.




19. A star with RA = 4h is in your meridian at a certain time. Which of the following stars will be on your meridian 2.5 hours from now?
A.RA = 6h 30m
B.RA = 4h 2m 30s
C.RA = 1h 30m
D.RA = 4h, since RA of a star does not change with time


20. The ecliptic is defined as the
A.band of constellations through which the Sun and Moon move in our sky.
B.line in the sky that is perpendicular to the Earth's spin axis.
C.line traced in our sky by the Moon each month against the background stars.
D.line traced in our sky by the Sun over one year against the background stars.


21. The ecliptic crosses the celestial equator at
A.two points, known as solstices.
B.one point only, known as the vernal equinox.
C.the meridian.
D.two points, known as equinoxes.


22. If we could observe background stars in daylight, how would the Sun appear to move against this background because of our motion on an orbiting Earth?
A.1° per day, from west to east
B.15° per hour, from east to west
C.1° per day, from east to west
D.15° per hour, from west to east


23. If the Earth's spin axis were perpendicular to the Earth's orbital plane (the ecliptic plane), then the seasons and seasonal variation would be
A.very little different from the present seasons.
B.much faster (shorter seasons), but less severe.
C.much more severe.
D.nonexistent.


24. In the northern hemisphere, summertime occurs when
A.the Earth is closest to the Sun in its elliptical orbit.
B.sunlight falls more directly on this hemisphere, heating it more than at other times of the year.
C.the Earth's equator is parallel to the plane of its orbit.
D.sunlight falls less directly on this hemisphere, spreading the heat out over a greater area.


25. During one complete year, an observer on the equator would be able to see what fraction of the overall sky?
A.50%
B.a variable amount, depending on the person's longitude
C.a variable amount, depending on which year
D.100%


26. The zodiac is a
A.band of sky extending 8° on each side of the celestial equator.
B.constellation representing a boat in the sky.
C.band of sky extending 8° on either side of the ecliptic.
D.band of sky 8° wide centered on the ecliptic.


27. Precession is
A.the motion of the Earth along its orbital path.
B.a very slow conical motion of the Earth's axis of rotation.
C.the occasional reversal of the direction of spin of the Earth.
D.the daily spinning motion of the Earth.


28. The phenomenon of precession of the Earth's spin axis is caused by the
A.varying intensity of sunlight on Earth throughout the year.
B.tidal ebb and flow of ocean waters on Earth.
C.variation of the spin rate of Earth.
D.gravitational pull of Moon and Sun on the Earth's equatorial bulge.


29. An observer's celestial meridian is the
A.arc joining the north and south celestial poles through the observer's zenith.
B.extension of the horizon onto the sky.
C.plane of the Earth's orbit extended onto the sky.
D.extension of the Earth's equator onto the sky.


30. Sidereal time is the more fundamental time, since it is a measure of the true rotation rate of Earth. Why then do we govern our lives by solar time rather than sidereal time?
A.We cannot divide the day into 24 equal hours of sidereal time.
B.In sidereal time, the Sun would reach the meridian early or late, sometimes by as much as 17 minutes at certain times of the year.
C.Different clocks tick at different rates depending on latitude in sidereal time.
D.We wish to remain in time with the Sun's illumination on Earth, with high Sun angle at about midday every day.



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