NOTE:  Those of you that had FORM 2 will, unfortunately, have to use the  scramble form in conjunction with the printout you obtain from the Physics Departmental Office to key your results to the exam answer key found below.

The FORM # for your exam is included in the information on the printout.

                                               Name __________________________
 

INSTRUCTIONS: Fill in your SSN and the FORM NUMBER of your exam on the
answer sheet. Choose the BEST answer for each question and mark your
choice on the answer sheet. Use a #2 pencil only. 

1. If one observatory site is described as having better seeing than
    another observatory site, what is it that is better at the better site?
 a. The winds are lighter at the better site, reducing vibrations in
    the telescope.
 b. The sky is more transparent (less haze) at that site, giving
    brighter images.
 c. There are more clear nights at that site.
*d. There is less air turbulence at that site, causing less twinkling
    and blurring of the images.

2. Which of the following types of telescopes is most seriously
    affected by chromatic aberration?
 a. radio telescope
 b. Cassegrain telescope
 c. Newtonian telescope
*d. refracting telescope

3. Planets move past the background stars as seen by someone on the
    Earth. What is the normal direction of this motion?
*a. From west to east because of the motion of the planet along its
    orbit.
 b. From east to west because of the motion of the planet along its
    orbit.
 c. From west to east because of the motion of the Earth along its
    orbit.
 d. From east to west because of the rotation of the Earth.

4. The word "planet" is derived from a Greek term meaning
 a. non-twinkling star.
 b. bright night-time object.
*c. wanderer.
 d. astrological sign.

5. Which of the following parameters will dictate whether a particular
    solar eclipse appears as a total or an annular eclipse to an
    observer on the center-line of the Moon's shadow?
 a. The distance of the Earth from the Sun at the time of eclipse.
*b. The distance of the Moon from the Earth at the time of eclipse.
 c. The time of day or night.
 d. The phase of the Moon, whether it is new, quarter or full.

6. At what time does a full Moon rise, approximately?
 a. at midnight
 b. at sunrise
 c. at noon
*d. at sunset

7. Which of the following statements correctly states the significance
    of Galileo's observation that Venus shows phases?
 a. The phases were interesting, but did not have any particular
    significance other than that.
 b. Since the phases were not correlated with angular size, they
    actually supported the geocentric theory more than the
    heliocentric theory.
*c. The phases were correlated with angular size in a way that
    supported the heliocentric theory.
 d. The phases showed that, like the Moon, Venus is always much
    closer to the Earth than is the Sun.

8. Suppose an astronomical satellite observes the Orion Nebula at a
    wavelength of 1250 nm. In what wavelength range is this satellite
    observing?
 a. ultraviolet
*b. infrared
 c. visible light
 d. x rays

9. In a telescope that uses adaptive optics to correct for atmospheric
    distortion of images, or "seeing".
*a. computer-controlled motors adjust the shape of the primary mirror
    many times per second.
 b. computer-controlled motors rapidly adjust the orientation of the
    individual mirrors in a multiple-mirror telescope (MMT).
 c. the light rays are focussed electronically, without the use of
    lenses or mirrors.
 d. a corrector lens compensates for image distortion by having its
    shape electronically controlled.

10. Where is a planet when it is moving most rapidly in its orbit?
 a. at the focus of its orbit
 b. at aphelion
 c. approaching the closest distance to the Sun
*d. at perihelion

11. The Sun's apparent path across our sky against the background stars
    (that would be seen if the daylight sky were not light) is known as
 a. the great circle.
*b. the ecliptic.
 c. the celestial equator.
 d. the celestial meridian.

12. The concept called "Occam's Razor" tells us that
 a. when two theories describe the same phenomena equally accurately,
    always choose the theory with the greater complexity.
 b. the theory that describes phenomena more accurately is more
    likely to be correct.
*c. when two theories describe the same phenomena equally accurately,
    always choose the simpler theory.
 d. the theory that is applicable to the greatest range of phenomena
    is more likely to be correct.

13. If an object has an orbit around the Sun that has an eccentricity of
    0.8, then the orbit is
 a. exactly circular.
 b. almost circular, but not quite.
*c. a long, thin ellipse.
 d. a straight line.

14. The PRIMARY reason for spreading many radio telescopes across a
    large area and combining the signals at a central station is
 a. to ensure that cloudy weather only affects a few of the
    telescopes, leaving the others to continue observing.
 b. to collect more radiation than would be possible with the same
    telescopes clustered together.
*c. to produce much sharper images of radio sources.
 d. to avoid interference between signals from the separate
    telescopes.

15. Why is the angular resolution of a 20-m diameter radio telescope
worse than that of a 0.5-m diameter optical telescope?
*a. Angular resolution gets worse as wavelength increases.
 b. Angular resolution gets worse as wavelength decreases.
 c. Angular resolution gets worse as mirror size increases.
 d. Optical mirrors suffer from chromatic aberration.

16. What evidence do we have that the Sun contains the element Iron?
 a. Magnetic fields exist in sunspots and on the Sun and these must
    be produced by iron in the same way that the Earth's magnetic
    field is generated.
*b. Solar spectra show absorption in spectral lines that are
    characteristic of iron and are unique to it.
 c. Scientists have collected meteorites that are almost pure iron
    that have originated in the Sun.
 d. The peak wavelength of the continuum spectrum of sunlight is
    characteristic of the emission spectrum of iron, as seen when a
    piece of iron is heated in the laboratory.

17. One essential condition for "seasons" to occur on a planet is that
*a. the planet have its spin axis tilted with respect to the
    perpendicular to its orbital plane.
 b. the planet's distance from the Sun varies.
 c. the planet have its axis perpendicular to its orbital plane.
 d. the planet have a thick atmosphere.

18. If a planet were to exist in our solar system in a circular orbit
    with a radius of 3 AU, about how long would it take to orbit the Sun
    once?
 a. 27 years
*b. 5.2 years
 c. 3 years
 d. 2.1 years

19. The ecliptic plane crosses the celestial equator
 a. at one point only, known as the summer solstice.
 b. at one point only, known as the vernal equinox.
 c. at two points, known as solstices.
*d. at two points, known as equinoxes.

20. Tycho Brahe
 a. improved the refracting telescope, which allowed him to extend
    Galileo's observations of the sky.
 b. developed a reflecting telescope, which used a curved mirror to
    focus the light.
 c. developed the first detailed heliocentric model for the solar
    system, which replaced the geocentric model of Ptolemy.
*d. made accurate measurements of planetary positions, which Kepler
    later used to find the shapes of planetary orbits.

21. If a star is described as being in the constellation Leo, a modern
 astronomer knows that it is
 a. inside our solar system.
 b. one of a few individual bright stars making up a picture (of a
    lion) in the sky.
 c. in a distant galaxy located in a particular direction from Earth.
*d. somewhere in a particular region of sky having definite
    boundaries.

22. An observer on the equator, in a period of one year, would be able
    to see what fraction of the overall sky?
 a. a variable amount, depending upon which year
 b. 50%
*c. 100%
 d. a variable amount, depending upon the person's longitude

23. On a given evening, you notice that the sunlit portion of the Moon
    has a crescent shape. This simple observation tells you
 a. nothing at all about the position of the Moon in space compared
    to that of Earth and the Sun.
 b. that the Moon is further from the Sun than is the Earth at that
    time.
*c. that the Moon is closer to the Sun than is the Earth at that
    time.
 d. that the line from the Earth to the Moon is exactly at right
    angles to the Sun-Earth line.

24. The term retrograde motion for a planet refers to
 a. the motion of a planet that orbits around the Sun in the opposite
    direction to the motion of the other planets.
 b. the apparent east to west motion of a planet as seen by an
    observer on the Earth, due to the Earth's rotation.
 c. the constant motion of a planet around its epicycle in the
    geocentric model of the solar system
*d. a reversal in the apparent direction of motion of a planet past
    the background stars as seen from the Earth.

25. Violet light differs from red light in that
 a. violet light travels more quickly (through a vacuum) than red
    light.
 b. violet light has a longer wavelength than red light.
*c. violet light has a shorter wavelength than red light.
 d. violet light travels more slowly (through a vacuum) than red
    light.

26. In telescopes, the angular resolution is worse for
 a. larger diameter lenses or mirrors and longer wavelength light (of
    other electromagnetic radiation).
*b. smaller diameter lenses or mirrors and longer wavelength light
    (or other electromagnetic radiation).
 c. smaller diameter lenses or mirrors and shorter wavelength light
    (of other electromagnetic radiation).
 d. larger diameter lenses or mirrors and shorter wavelength light
    (or other electromagnetic radiation).

27. Many amateur astronomers have telescopes with mirrors 20 cm (1/5 m)
    in diameter. In comparison, the largest astronomical telescope in
    the world is the Keck telescope, with a diameter of 10 m. How many
    times larger is the light-gathering power of the Keck telescope
    than a 20-cm telescope?
 a. 125,000 times larger
 b. 7 times larger
 c. 50 times larger
*d. 2,500 times larger

28. The first person to derive the elliptical shape of planetary orbits
    from basic physics and mathematics (not from observations of
    planetary positions) was
 a. Kepler.
 b. Copernicus.
*c. Newton.
 d. Galileo.

29. The Earth exerts a force on you as you stand on its surface. What is
    the size of the force exerted on the Earth by you, when compared to
    the above force?
 a. Twice as large, because of the Earth's rotation.
 b. Zero, you do not exert a force on the Earth.
 c. Very small, because your mass is small compared to that of Earth.
*d. The same.

30. A small particle of interplanetary material is heated by friction
    from a temperature of 400K to 4000K as it falls into the atmosphere
    of the Earth and produces a meteor or a shooting star in our sky. If
    this object behaves like a perfect black body over this short time,
    how will its emitted radiation change as it is heated?
*a. Its total emitted intensity will rise by a factor of 10,000 while
    its peak wavelength will become shorter by a factor of 10, from
    infrared to red visible light.
 b. Its total intensity will rise by a factor of 10, while its peak
    wavelength will become shorter by a factor of 10, moving from
    infrared to red visible light.
 c. Its total intensity will rise by a factor of 10,000 while its
    peak wavelength will become longer by a factor of 10, moving from
    visible to infrared or heat radiation.
 d. Its intensity will rise by a factor of 100 while the peak
    wavelength of emitted light will become shorter by a factor of
    100, moving from infrared to ultra-violet.

31. The Copernican system for planetary motions is
 a. Sun-centered, with planets moving in elliptical orbits, the Sun
    being at one focus of the ellipse.
 b. Earth-centered, with planets moving in patterns of epicycles
    around the Earth.
 c. Earth-centered, with planets, the Sun and stars mounted on
    crystal spheres, pivoted to allow the correct planetary motions.
*d. Sun-centered, with planets moving in perfect circles around the
    Sun.

32. Kepler's first law states:
 a. The orbit of a planet about the Sun is an ellipse with the Sun at
    the center.
 b. The orbit of a planet about the Sun is a circle with the Sun at
    the center.
 c. The orbit of a planet about the Sun is an oval with the Sun at
    the center.
*d. The orbit of a planet about the Sun is an ellipse with the Sun at
    one focus.

33. Which one of the following wavelength regions MUST be observed from
    space, since no energy in this region reaches the ground?
 a. radio
 b. infrared
 c. visible light
*d. x rays

34. 1 arc second is equal to
 a. 1/60 of a full circle.
 b. 1/360 of a full circle.
*c. 1/3600 degree.
 d. 1/60 degree.

35. A major contribution of Ptolemy to the development of astronomy was
    to
*a. derive a mathematical model for the solar system, in which
    planets move in epicycles and the epicycles orbited the Earth.
 b. originate the idea of a geocentric (Earth-centered) cosmogony,
    that was later developed mathematically by Aristarchus.
 c. derive a mathematical model for the solar system, in which
    planets move around the Earth in elliptical orbits, moving
    fastest when closest to the Earth.
 d. derive a mathematical model for the solar system, in which
    planets move around the Sun in circular orbits.

36. A particular photon of ultraviolet (UV) light has a wavelength of
    200 nm and a photon of infrared (IR) light has a wavelength of 2000
    nm. What is the energy of the UV photon compared to the IR photon?
 a. It has 1/10 of the energy of the IR photon.
 b. It has 100 times more energy than the IR photon.
*c. It has 10 times more energy than the IR photon.
 d. It has 1/100 of the energy of the IR photon.

37. Which of the following factors makes it far more likely that a
    person will have seen a total lunar eclipse than a total solar
    eclipse?
*a. A total lunar eclipse can be seen by people on most of the
    nighttime side of Earth while a specific total solar eclipse can
    only be seen by people within a narrow strip of the Earth's
    surface.
 b. A total lunar eclipse occurs at full Moon when the Moon is bright
    and high in the sky while a total solar eclipse occurs at new
    Moon when the Moon is dark and low in the sky.
 c. Total solar eclipses occur much less frequently than total lunar
    eclipses.
 d. The Moon appears brighter during a total lunar eclipse than does
    the Sun during a total solar eclipse.

38. If you were on Mars, which of the following "planets" would never be
    seen as a crescent?
*a. Jupiter
 b. Earth
 c. Earth's Moon
 d. Venus

39. How much of the total surface of the Moon is illuminated by the Sun
    when it is at quarter phase?
 a. all of it
 b. very little
 c. one quarter
*d. one half

40. As a new star evolves from cool dust and gas to a hot star, the peak
    wavelength of its spectrum of emitted electromagnetic radiation will
*a. change from the infrared to the visible wavelengths.
 b. increase from the visible to infrared wavelengths.
 c. remain the same.
 d. change from the ultraviolet to the visible range.