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Final Exam: December 2015 Number of pages: 18
Course: ASTR 1P01 Number of students: 828
Examination date: 18 December 2015 Time limit: 2 hours Time of Examination: 16:00 – 18:00 Instructor: S. D’Agostino
Answer all questions on the scantron sheet provided.
No aids are permitted except for a non-programmable calculator. Use or pos- session of unauthorized materials will automatically result in the award of a zero grade for this examination.
Return both the exam script and your scantron sheet when you leave the exam room.
Each question is worth 1 mark. Total number of marks: 100.
1. The diameter of Venus is Earth’s diameter.
(a) slightly less than (b) about twice as large as
(c) about five times as large as (d) about ten times as large as
2. The radius of the orbit of Mars around the Sun is about times as large as the radius of Earth’s orbit around the Sun.
(a) 1.5 (b) 10
(c) 50 (d) 100
3. The mass of the Sun is about times the mass of the Earth.
(a) 30 (b) 300
(c) 3,000 (d) 30,000
(e) 300,000
4. It takes light reflected from the Moon approximately to reach the Earth.
(a) 1 second (b) 1 minute
(c) 1 hour (d) 1 day
5. The speed of light in vacuum is approximately (a) 300,000 km/year.
(b) 300,000 km/h.
(c) 300,000 km/min.
(d) 300,000 km/s.
(e) much faster than any of the other alternatives listed here.
6. One astronomical unit (1 AU) is approximately equal to (a) 150,000 km.
(b) 150,000,000 km.
(c) 150,000,000,000 km.
(d) 150,000,000,000,000 km.
7. Ancient astronomers recognized that planets are different from stars because they observed
(a) that planets are made of rock, whereas stars are made of gas.
(b) through telescopes that planets appear as disks, whereas stars appear as points.
(c) that planets are much closer to us than stars.
(d) over time, planets appear to move against the relatively fixed background stars.
8. The Sun appears to rise in the east and set in the west because the Earth rotates (a) from east to west.
(b) from west to east.
(c) from north to south.
(d) from south to north.
9. Since 2006, Pluto has been classified as (a) an exoplanet.
(b) a midget planet.
(c) a dwarf planet.
(d) a minor planet.
(e) a planetesimal.
10. The Big Bang occurred about years ago.
(a) 14 thousand (b) 14 million
(c) 14 billion (d) 14 trillion
11. The approximate number of stars in the Milky Way galaxy is (a) 100 thousand.
(b) 100 million.
(c) 100 billion.
(d) 100 trillion.
12. Most of the solar system’s asteroids are located in a region between the orbits of Mars and Jupiter called
(a) the asteroid cummerbund.
(b) the asteroid bracelet.
(c) the asteroid necklace.
(d) the asteroid belt.
13. We do not see solar eclipses every time the Moon is new because
(a) sometimes the Moon is actually pre-owned but the galactic dealership is fraudu- lently passing it off as new.
(b) the Moon is usually on the wrong side of the Earth to be seen.
(c) the Moon’s orbit around the Earth is tilted relative to the Earth’s orbit around the Sun.
(d) the Moon can only be eclipsed once every 18 years.
14. When the Moon rises at about sunrise, its phase is (a) new.
(b) first quarter.
(c) full.
(d) third quarter.
15. When the Moon rises at about mid-day, its phase is (a) new.
(b) first quarter.
(c) full.
(d) third quarter.
16. When the Moon rises at about sunset, its phase is (a) new.
(b) first quarter.
(c) full.
(d) third quarter.
17. When the Moon rises at about midnight, its phase is (a) new.
(b) first quarter.
(c) full.
(d) third quarter.
18. When the Moon’s phase is waning gibbous, it sets (a) between sunrise and mid-day.
(b) between mid-day and sunset.
(c) between sunset and midnight.
(d) between midnight and sunrise.
19. When the Moon’s phase is waning crescent, it sets (a) between sunrise and mid-day.
(b) between mid-day and sunset.
(c) between sunset and midnight.
(d) between midnight and sunrise.
20. When the Moon’s phase is waxing crescent, it sets (a) between sunrise and mid-day.
(b) between mid-day and sunset.
(c) between sunset and midnight.
(d) between midnight and sunrise.
21. When the Moon’s phase is waxing gibbous, it sets (a) between sunrise and mid-day.
(b) between mid-day and sunset.
(c) between sunset and midnight.
(d) between midnight and sunrise.
22. The total frequency of eclipses (including both solar and lunar) is typically about (a) 4 or 5 per month.
(b) 4 or 5 per year.
(c) 4 or 5 per decade.
(d) 4 or 5 per century.
23. On the summer solstice in the northern hemisphere, the Sun rises (a) directly east.
(b) north of east.
(c) south of east.
(d) [It depends on your exact location in the northern hemisphere.]
24. On the winter solstice in the northern hemisphere, the Sun rises (a) directly east.
(b) north of east.
(c) south of east.
(d) [It depends on your exact location in the northern hemisphere.]
25. On an equinox in the northern hemisphere, the Sun rises (a) directly east.
(b) north of east.
(c) south of east.
(d) [It depends on your exact location in the northern hemisphere.]
26. In the northern hemisphere, in the two months from January to February, the sun rises (a) a little further north each day.
(b) a little further south each day.
(c) a little further east each day.
(d) a little further west each day.
27. In the northern hemisphere, in the two months from April to May, the sun rises (a) a little further north each day.
(b) a little further south each day.
(c) a little further east each day.
(d) a little further west each day.
28. One of Aristotle’s great astronomical advances was
(a) his inspiration of “The Big Aristotle,” Shaquille O’Neal.
(b) his careful observations of the Moon.
(c) his pioneering observations of the rings of Saturn.
(d) his compelling arguments that the Earth is spherical.
29. One of Eratosthenes’s great astronomical advances was that he was the first to (a) argue that the Earth is at the centre of the solar system.
(b) argue that the Sun is at the centre of the solar system.
(c) accurately estimate the size of the Earth.
(d) accurately estimate the distance from the Earth to the Sun.
30. One of Aristarchus’s great astronomical advances was that he was the first to (a) plot the orbits of all the terrestrial planets.
(b) determine the distance of each terrestrial planet to the Sun.
(c) determine the sizes of each terrestrial planet.
(d) determine the relative sizes of the Earth, Moon, and Sun.
31. The strongest ancient argument in favour of an Earth-centred solar system was that (a) the Earth is much too massive to move.
(b) it would be much more windy on Earth if it moved.
(c) the Sun was the ruler of the Earth in ancient mythology.
(d) stellar parallax was not observed.
32. The orbits of the planets around the Sun
(a) are in various parts of the sky, somewhat like bees buzzing around a beehive.
(b) are always in planes, but the planes are oriented randomly in the sky.
(c) lie approximately close to a single plane in some seasons, but far from the ecliptic in others.
(d) lie close to a single plane.
33. The reason for the apparent retrograde motions of the planets is that
(a) the Earth moves at a different speed and in a different orbit compared to other planets.
(b) sometimes the gears in the celestial spheres get “stuck,” and it takes a few weeks for them to move normally again.
(c) some planets have nostalgia for the 1970s and therefore occasionally “go retro.”
(d) some planets sometimes orbit the Sun in the sense opposite to Earth’s orbital sense.
34. The Earth-centred model of the solar system was developed to its highest degree by (a) Pandora.
(b) Plato.
(c) Ptolemy.
(d) Pythagoras.
35. The Sun-centred model of the solar system, which was originally championed by , was revived in the Renaissance by .
(a) Ra, Sheed
(b) Hipparchus, Galileo (c) Almagest, Kepler
(d) Aristarchus, Copernicus 36. Tycho Brahe
(a) had a blank space, baby, and wrote Galileo’s name.
(b) was the first astronomer to observe stellar parallax.
(c) was the first astronomer to observe a comet.
(d) was the greatest naked-eye observer in the history of astronomy.
(e) [None of the above.]
37. After many years of number-crunching, determined that the orbits of the planets were ellipses, and he also determined relationships satisfied by various proper- ties of the planetary orbits.
(a) Nicolaus Copernicus (b) Galileo Galilei
(c) Johannes Kepler (d) Ada Lovelace
(e) Isaac Newton
38. Convincing evidence that the Sun is the centre of the solar system was obtained thanks to the careful observations and arguments of
(a) Aristarchus.
(b) Simone de Beauvoir.
(c) Albert Camus.
(d) Galileo Galilei.
(e) Isaac Newton.
39. Ockham’s razor is
(a) used only in the finest astronomical barber shops.
(b) a device used by ancient Greek astronomers to measure the angle between the Sun and the planets.
(c) another term used to describe the heliocentric model of the solar system.
(d) a metaphor for the process of discriminating between scientific models based on their relative simplicity.
40. Newton’s first law of motion states that
(a) if the big game is on TV, I ain’t getting off the couch.
(b) if the net force acting on an object is zero, then the object maintains its state of continuous rest or its state of motion at a constant speed.
(c) if the net force acting on an object is zero, then the object maintains its state of continuous rest or its state of motion in a straight line at a constant acceleration.
(d) if the net force acting on an object is zero, then the object maintains its state of continuous rest or its state of motion in a straight line at a constant speed.
41. The Earth orbits the Sun because
(a) it wants to hang out with the cool celestial objects.
(b) of Newton’s first law of motion, which says that a body in motion tends to stay in motion.
(c) of the gravitational force exerted on it by the Sun.
(d) the Earth and Sun form a binary Fourier-transform pair.
42. Newton’s second law of motion states that the acceleration of an object is equal to (a) the net force acting on it divided by its velocity.
(b) its velocity divided by the net force acting on it.
(c) the net force acting on it divided by its mass.
(d) its mass divided by the net force acting on it.
43. Newton’s second law of motion states that the direction of an object’s is the same as the direction of the .
(a) acceleration, velocity
(b) acceleration, net force exerted on the object (c) acceleration, speed
(d) velocity, net acceleration exerted on the object
44. If a moving object changes its speed or direction, then (a) the net force acting on the object is zero.
(b) the net force acting on the object is not zero.
(c) [The net force acting on the object might or might not be zero, depending on the object’s mass.]
(d) [The net force acting on the object might or might not be zero, depending on the object’s velocity.]
45. Newton’s third law states that
(a) if you’re running through the 6 with your woes, and don’t know yourself, you’ll be crossed over by CoJo.
(b) when two objects interact, the more massive one exerts a greater force on the less massive one, in the same ratio as the masses.
(c) when two objects interact, each exerts a force on the other, and the two forces have the same magnitude and opposite directions.
(d) when two objects interact, the forces each exerts on the other are directly pro- portional to the masses of the objects and the square of the distance separating the objects.
46. If the masses of the Earth and the Moon were to suddenly triple, while the distance between them remained the same, then the gravitational force on each of them exerted by the other would
(a) increase by a factor of 3.
(b) decrease by a factor of 3.
(c) increase by a factor of 9.
(d) decrease by a factor of 9.
(e) [There would be no change in the gravitational force.]
47. If the masses of the Earth and the Moon were to suddenly triple, and the distance between them also tripled, then the gravitational force on each of them exerted by the other would
(a) increase by a factor of 3.
(b) decrease by a factor of 3.
(c) increase by a factor of 9.
(d) decrease by a factor of 9.
(e) [There would be no change in the gravitational force.]
48. If two beams of visible light have different wavelengths, we would notice this because they also have different
(a) masses.
(b) accelerations.
(c) forces.
(d) colours.
49. Light is
(a) “up we go, up we go!”
(b) a hydrodynamic wave.
(c) a torsional wave.
(d) an electromagnetic wave.
(e) [None of the above, as light is formed from particles, not waves.]
50. Wave-particle duality means that
(a) promoters will soon be staging a wave-particle cage-match and charging $89.95 on pay-per-view.
(b) your dual-exhaust jalopy rumbles like a wave but zooms like a particle.
(c) light sometimes behaves like a wave and sometimes behaves like a particle.
(d) some things in the universe behave like waves and other things behave like parti- cles.
51. The brightness (also known as intensity) of light is a measure of (a) its intelligence.
(b) its energy.
(c) its force.
(d) its wavelength.
52. Photon A has a longer wavelength than photon B, which means that the energy of photon A is the energy of photon B.
(a) greater than (b) less than
(c) [The energy of a photon is not related to its wavelength.]
53. The wavelength of blue light
(a) depends on how much of the Labbatt product that you’ve drunk in one sitting.
(b) is about 450 nanometres.
(c) is about 450 millimetres.
(d) is about 450 centimetres.
(e) is about 450 kilometres.
54. Infrared radiation is invisible, but Herschel discovered it in 1800 when he projected a spectrum of sunlight onto a table top and placed a thermometer just off
(a) the blue end of the visible spectrum.
(b) the green end of the visible spectrum.
(c) the red end of the visible spectrum.
(d) the yellow end of the visible spectrum.
55. When Herschel placed his thermometer as described in the previous question, he no- ticed that its temperature reading
(a) increased.
(b) decreased.
(c) remained constant.
(d) fluctuated wildly.
56. As the temperature of a glowing object increases, the object radiates electromagnetic waves more strongly at all wavelengths, but the peak wavelength
(a) increases.
(b) decreases.
57. When an electron makes a “jump” from a higher energy level to a lower energy level in an atom,
(a) the atom moves about with greater speed.
(b) the atom moves about with greater temperature.
(c) a photon of electromagnetic radiation is emitted.
(d) [It depends on whether it’s a “high jump” or a “long jump.”]
58. The chemical composition of a glowing object, such as a star, can be deduced by analyzing its
(a) discrete emission spectrum.
(b) indiscrete emission spectrum.
(c) continuous spectrum.
(d) baryonic spectrum.
59. The temperature of a glowing object, such as a star, can be deduced by analyzing its (a) discrete emission spectrum.
(b) indiscrete emission spectrum.
(c) continuous spectrum.
(d) baryonic spectrum.
(e) discrete absorption spectrum.
60. The chemical composition of a star’s atmosphere can be deduced by analyzing its (a) discrete emission spectrum.
(b) continuous spectrum.
(c) baryonic spectrum.
(d) discrete absorption spectrum.
61. If an object has spectral lines shifted to shorter wavelengths, then the object is (a) moving away from us.
(b) moving towards us.
(c) maintaining the same distance to us.
(d) not moving relative to us.
62. The largest modern optical telescopes are reflectors because
(a) refractors make astronomers so angry they get bent out of shape.
(b) reflectors can be cooled without using liquid nitrogen.
(c) large lenses are too expensive and suffer from various aberrations.
(d) reflectors can be built with greater amplification.
63. A large telescope mirror is built out of a block of glass that is shaped, polished, and then coated with a thin layer of
(a) vaseline, for soft-focus magazine photographs.
(b) aluminum or other highly reflective material.
(c) teflon or other highly reflective material.
(d) gold or other highly reflective material.
64. Increasing the diameter of the objective lens of an optical telescope also (a) increases its light gathering power only.
(b) increases its resolving power only.
(c) increases its light gathering power and resolving power.
(d) [None of the above.]
65. Radio telescopes
(a) are optical telescopes that are remote controlled by radio communication.
(b) are optical telescopes whose results were communicated by radio back in the early days.
(c) are optical telescopes that are “ganged” by radio links.
(d) detect radio waves emitted by astronomical objects.
66. Charge-coupled devices (CCDs) are better than photographic film because (a) the coupling produces little baby charged devices, which is a nice bonus.
(b) CCDs attract a lot fewer paparazzi than photographic film.
(c) CCDs are more sensitive to light than photographic film.
(d) CCDs are more effective at detecting chargalinos than photographic film.
67. An interferometer is used so that
(a) two widely-spaced mirrors act like one giant telescope with increased magnifica- tion.
(b) two widely-spaced mirrors act like one giant telescope with increased resolving power.
(c) by putting one mirror above the other the instrument can be made much smaller.
(d) light can be detected at wavelengths not available to single telescopes.
68. Observatories are built in space
(a) because it’s a good excuse for astronomers to vacation at interplanetary hot spots.
(b) because they are much less expensive than ground-based observatories.
(c) because they can thereby last forever.
(d) to avoid atmospheric blurring.
69. One way to increase the light-gathering power of a reflecting telescope is to (a) replace its mirror with one that has larger diameter.
(b) make its tube longer.
(c) increase the magnification of its eyepiece.
(d) change the focus from Cassegrain or prime to Newtonian.
70. One can calculate the distance to a nearby star based on its measured parallax. Stars with larger parallaxes are
(a) farther away from us.
(b) nearer to us.
(c) the same distance to us as other stars.
(d) [There is no relation between stellar parallax and distance.]
71. Stars are composed mainly of
(a) sugar and spice, and everything nice.
(b) very hot magma mixed with molten metals, with traces of other elements.
(c) hydronium and helium, with traces of other elements.
(d) hydrogen and helium, with traces of other elements.
72. The diameter of a typical star is about times the Earth’s diameter.
(a) 100 (b) 10,000
(c) 1,000,000 (d) 100,000,000
73. The colour of a star (more accurately, the wavelength at which a star radiates most strongly) is directly related to the star’s through Wien’s law.
(a) radius (b) mass
(c) temperature (d) density
74. The luminosity of a star is
(a) a measure of the star’s colour.
(b) the total number of photons the star radiates per second.
(c) the total amount of energy the star radiates per second.
(d) the total amount of the star’s radiating surface area.
75. It follows from the Stefan-Boltzmann law that
(a) if you don’t get up on Stephen Curry he’ll bury a three-pointer.
(b) if two stars have the same luminosity, the hotter one has greater size.
(c) if two stars have the same size, the hotter one has greater luminosity.
(d) if two stars have the same density, the larger one has greater luminosity.
76. A cool but very luminous star (a) buys his or her clothes on Etsy.
(b) has a very small radius.
(c) has a very large radius.
(d) has a very small mass.
77. A hot star that is not very luminous (a) makes frequent appearances on TMZ.
(b) has a very large radius.
(c) has a very small radius.
(d) has a very large mass.
78. Cooler, less luminous main sequence stars have (a) relatively high masses.
(b) relatively low masses.
(c) similar masses to hotter main-sequence stars.
(d) masses that vary widely.
79. Stars represented by positions in the upper-right part of the H-R diagram (a) are mainly white dwarfs.
(b) are bright and hot.
(c) are dim and cool.
(d) are mainly red giants.
(e) [None of the above.]
80. Stars represented by positions in the lower-left part of the H-R diagram (a) are mainly white dwarfs.
(b) are bright and hot.
(c) are dim and cool.
(d) are mainly red giants.
(e) [None of the above.]
81. Stars represented by positions in the upper-left part of the H-R diagram (a) are mainly white dwarfs.
(b) are bright and hot.
(c) are dim and cool.
(d) are mainly red giants.
(e) [None of the above.]
82. Stars represented by positions in the lower-right part of the H-R diagram (a) are mainly white dwarfs.
(b) are bright and hot.
(c) are dim and cool.
(d) are mainly red giants.
(e) [None of the above.]
83. The Sun is found
(a) along the main sequence of the H-R diagram.
(b) in the upper-left part of the H-R diagram.
(c) in the upper-right part of the H-R diagram.
(d) in the lower-left part of the H-R diagram.
(e) in the lower-right part of the H-R diagram.
84. Using Eddington’s mass-luminosity relation, measuring a star’s allows us to determine the stars’s .
(a) mass, luminosity (b) luminosity, mass
(c) radius, luminosity and mass (d) temperature, luminosity and mass
85. Analyzing light curves from eclipsing binary stars (specifically, measuring various time intervals) allows us to measure the stars’
(a) masses.
(b) luminosities.
(c) diameters.
(d) temperatures.
86. The temperature of the Sun at its centre is its temperature at its surface.
(a) much greater than (b) much less than
(c) about the same as
(d) [The temperature at the centre is unknown, because we can’t access the Sun’s centre.]
87. The forces that keep most of the Sun’s gas from escaping are (a) electrostatic forces between ions in its interior.
(b) due to gas pressure.
(c) gravitational.
(d) [Nothing stops the Sun’s gas from escaping.]
88. As you move from the outer layers of the Sun towards the centre of the Sun, its density (a) remains approximately constant.
(b) decreases.
(c) increases.
89. Most stars are born with approximately the following composition.
(a) About 50% hydrogen, about 50% helium, and less than 2% heavier elements.
(b) About 60% hydrogen, about 40% helium, and less than 2% heavier elements.
(c) About 75% hydrogen, about 25% helium, and less than 2% heavier elements.
(d) About 90% hydrogen, about 10% helium, and less than 2% heavier elements.
90. Since most stars are born with approximately the same composition, what character- istic most determines how their evolution will differ?
(a) The quality of the parenting that they received.
(b) The time at which they were formed.
(c) Their initial spectrum.
(d) Their initial mass.
(e) The location where they were formed.
91. Most of the nuclear fusion that fuels the Sun’s radiation takes place in the Sun’s (a) hot new night club.
(b) radiative zone.
(c) conductive zone.
(d) core.
92. Near the Sun’s core, the net outward energy flow occurs primarily by (a) cavitation.
(b) conduction.
(c) convection.
(d) radiation.
(e) Donald Trump’s hot air pushing the energy away.
93. Near the Sun’s surface, the net outward energy flow occurs primarily by (a) cavitation.
(b) conduction.
(c) convection.
(d) radiation.
94. The Sun is supported against its own crushing weight by (a) its rapid rotation.
(b) magnetic forces.
(c) gravitational forces.
(d) gas pressure.
(e) electrostatic forces.
95. Sunspots increase and decrease in number in a cycle that has peaks approximately every
(a) 11 years.
(b) 22 years.
(c) 33 years.
(d) 44 years.
96. The Sun’s upper atmosphere is extremely hot because (a) it absorbs neutrinos flowing from the Sun’s core.
(b) of nuclear fusion in the upper atmosphere.
(c) of nuclear fission in the upper atmosphere.
(d) [This is currently a mystery.]
97. During the day, about a trillion solar neutrinos pass through your body. At night the number is
(a) zero.
(b) much less, but not zero.
(c) about half as much.
(d) about the same.
(e) much more.
98. The Sun’s equator rotates (a) faster than near the poles.
(b) at the same rate as near the poles.
(c) slower than near the poles.
99. The internal balance of forces in the Sun is known as (a) supercalifragilisticexpialidocioustatic balance.
(b) hydrostatic balance.
(c) magnetohydrostatic balance.
(d) electromagnetostatic balance.
100. The solar wind
(a) occurs when the Sun has overeaten, especially spicy food.
(b) is usually followed by solar rain.
(c) occurs in explosive eruptions such as prominences and solar flares.
(d) is a steady, slight, and tenuous flow of mainly hydrogen and helium.