Download Return both exam and scantron sheet when you

Page 1 of 17
BROCK UNIVERSITY
Number of pages: 17
Number of Students: 500
Number of hours: 2
Instructor: B.Mitrović
Final Exam December 2014
Course: ASTR 1P01
Date of Examination: December 5, 2014
Time of Examination: 20:00–22:00
No examination aids other than those specified on this examination script are permitted (FHB
III: 9.1.2.B). Use or possession of unauthorized materials will automatically result in the award
of a zero grade for this examination.
PLEASE RECORD YOUR STUDENT NAME AND NUMBER ON THE SCANTRON SHEET BEFORE YOU DO ANYTHING; USE AN HB PENCIL ON THE
SCANTRON SHEET. THERE ARE 100 QUESTIONS.
Return both exam and scantron sheet when you leave
the gym
1. Which of these stars has the hottest surface?
(a) A star that emits most energy at 475 nm.
(b) A star that emits most energy at 570 nm.
(c) A star that emits most energy at 650 nm.
2. The parallax angle of a star is 0.2 seconds of arc. Its distance in light-years (ly) is
(a) 0.2 ly.
(b) 0.65 ly.
(c) 5 ly.
(d) 16 ly.
3. A star in the binary system Capella has the same surface temperature as the Sun, but
its radius is 9 times larger than the radius of the Sun. The luminosity of that star is
the luminosity of the Sun.
(a) equal to
(b) 9 times larger than
(c) 81 times larger than
(d) 9 times smaller than
(e) 81 times smaller than
1
Course: ASTR1P01
Date: December 5, 2014
page 2 of 17 pages
4. Which of these types of stars is most commonly observed?
(a) Red giants.
(b) Main sequence stars.
(c) White dwarfs.
5. In order to determine a star’s distance using the spectroscopic parallax one needs to
know the star’s
(a) parallax angle.
(b) spectral class and surface temperature.
(c) spectral class and luminosity class.
(d) luminosity class and radius.
6. The absorption lines in the spectrum of a red giant are broader than those in the spectrum of a main sequence star.
(a) True.
(b) False.
7. Which of these main sequence stars has the highest luminosity?
(a) Spica with a mass of 10 solar mass.
(b) Sirius with a mass of 2 solar mass.
(c) Sun with a mass of 1 solar mass.
(d) Barnard’s star with a mass of 0.144 solar mass.
8. Which of these main sequence stars will have the longest life?
(a) Spica with a mass of 10 solar mass.
(b) Sirius with a mass of 2 solar mass.
(c) Sun with a mass of 1 solar mass.
(d) Barnard’s star with a mass of 0.144 solar mass.
9. Sirius B is
(a) a red giant.
(b) a main sequence star.
(c) a white dwarf.
2
Course: ASTR1P01
Date: December 5, 2014
page 3 of 17 pages
10. The spectral class of a star provides information about its
(a) mass.
(b) luminosity.
(c) temperature.
(d) chemical composition.
11. If the energy of a photon is not equal to the energy difference between the energy level
occupied by an electron and an empty higher energy level, the photon
(a) will not be absorbed by the atom.
(b) will be absorbed by the atom.
12. Stars S and U are equally bright but the distance of S is six times greater than the
the luminosity of U
distance of U. The luminosity of S is
(a) 6 times larger than
(b) 6 times smaller than
(c) 36 times larger than
(d) 36 times smaller than
13. Stars U and W form a binary system and the mass of U is twice that W. Their center
of mass is closer to star
(a) U.
(b) W.
14. Stars Rigel and Betelgeuse in Orion have nearly equal luminosity of about 120,000 solar luminosity. The surface temperature of Rigel is about 12,000 K and the surface
temperature of Betelgeuse is about 3000 K. This implies that
(a) Rigel is closer than Betelgeuse.
(b) Rigel has a smaller radius than Betelgeuse.
(c) Rigel has the same color as Betelgeuse.
(d) [None of the above.]
15. The spectra of stars in the Andromeda galaxy are blueshifted. This implies that the
Andromeda is
our galaxy.
(a) approaching
(b) receding from
3
Course: ASTR1P01
Date: December 5, 2014
page 4 of 17 pages
16. When a star in the binary system is moving perpendicular to the line of site the wavelengths of the absorption lines in its spectrum are
(a) redshifted.
(b) blueshifted.
(c) [None of the above.]
17. The mass of a main sequence star can be deduced from its
(a) spectrum using the Wien’s law.
(b) luminosity using the Stefan-Boltzmann law.
(c) luminosity using the Eddington’s mass luminosity relation.
18. The chemical composition of stars is determined from their
(a)
(b)
(c)
(d)
distance.
luminosity.
absorption spectra.
temperature.
19. The second most abundant chemical element in main sequence stars is
(a)
(b)
(c)
(d)
hydrogen.
oxygen.
helium.
nitrogen.
20. The closer the star, the smaller is its parallax angle.
(a) True.
(b) False.
21. The distance to the Sun is determined by
(a) measuring its parallax angle.
(b) measuring the time of flight of a radar pulse that is reflected back by the Sun.
(c) spectroscopic parallax from its luminosity and surface temperature.
22. To determine the luminosity of the Sun from its measured brightness it is necessary to
know its
(a) radius.
(b) temperature.
(c) distance
4
Course: ASTR1P01
Date: December 5, 2014
page 5 of 17 pages
23. A high temperature is needed for the fusion of protons in the core of the Sun in order to
(a) increase the density of protons in the core.
(b) increase the strength of the attractive strong nuclear force.
(c) overcome a large electrical repulsion between the protons at short distances.
(d) [None of the above.]
24. The fusion of protons (nuclei of hydrogen) in the core of a star will not begin unless its
temperature is at least
(a) 10,000 K.
(b) 100,000 K.
(c) 1,000,000 K.
(d) 10,000,000 K.
(e) 100,000,000 K.
25. The fusion of two protons into the nucleus of deuterium with release of positron, neutrino
and energy happens on average once in 14 billion years (the age of the Universe). Yet,
there is a very large number of these fusion reactions happening in the Sun every second
because
(a) the temperature in the fusion core is very high.
(b) the number of hydrogen nuclei in the Sun is very high.
(c) the pressure in the fusion core is very high.
26. The mass of deuterium formed by fusion of two protons in the first step of the protonproton chain is
the total mass of the two protons before the fusion.
(a) greater than
(b) equal to
(c) less than
27. A positron is released when two protons fuse into deuterium because the total
must be conserved (i.e. unchanged) during fusion.
(a) mass
(b) electric charge
(c) number of particles
5
Course: ASTR1P01
Date: December 5, 2014
page 6 of 17 pages
28. The number of fusion reactions of hydrogen into helium each second in the core of the
Sun can be obtained by dividing the luminosity of the Sun with the
(a) energy carried by photons produced in each fusion reaction.
(b) energy carried by neutrinos produced in each fusion reaction.
(c) total energy (i.e. that of photons and neutrinos) produced in each fusion reaction.
(d) [None of the above.]
29. Each proton-proton chain fusion reaction produces
(a) one neutrino.
(b) two neutrinos.
(c) four neutrinos.
(d) [None of the above.]
30. Over time the luminosity of the Sun
(a) slowly increases.
(b) slowly decreases.
(c) remains the same.
31. The Sun maintains the hydrostatic equilibrium
(a) by spinning fast.
(b) by pressure-temperature thermostat.
(c) by reducing its mass over time.
(d) by fusing hydrogen into helium.
32. On average it takes about million years for the neutrinos produced in the fusion core of
the Sun to reach its surface.
(a) True.
(b) False.
33. As the photons produced in the fusion core of the Sun propagate to its surfaces their
wavelength
(a) decreases.
(b) increases.
(c) remains unchanged.
6
Course: ASTR1P01
Date: December 5, 2014
page 7 of 17 pages
34. The magnetic field produced by the Sun within the region of a sunspot is
average magnetic field on the surface of the Sun.
the
(a) smaller than
(b) larger than
(c) equal to
35. Parts of the Sun which are closer to the solar equator move slower than the parts which
are farther away.
(a) True.
(b) False.
36. What prevents the hot gas carried by the convection currents to reach the area of a
sunspot?
(a) Differential rotation of the Sun.
(b) Solar dynamo.
(c) The material held in place by the magnetic field.
37. When does the intensity of the solar wind have the highest value?
(a) During the solar activity maximum as measured by the number of sunspots.
(b) During the solar activity minimum as measured by the number of sunspots.
(c) The intensity of the solar wind does not depend on the solar activity.
38. When are the aurorae on Earth least frequent?
(a) During the solar activity maximum as measured by the number of sunspots.
(b) During the solar activity minimum as measured by the number of sunspots.
(c) The frequency of the aurorae on Earth does not depend on the solar activity.
39. When are the solar flares most frequent?
(a) During the solar activity maximum as measured by the number of sunspots.
(b) During the solar activity minimum as measured by the number of sunspots.
(c) The frequency of the solar flares does not depend on the solar activity.
7
Course: ASTR1P01
Date: December 5, 2014
40. When is the concentration of
14
page 8 of 17 pages
C in the Earth’s atmosphere lowest?
(a) During the solar activity maximum as measured by the number of sunspots.
(b) During the solar activity minimum as measured by the number of sunspots.
(c) The concentration of
activity.
14
C in the Earth’s atmosphere does not depend on the solar
41. During the Maunder minimum the temperature in Europe and North America was
(a) lower than normal.
(b) higher than normal.
(c) It had the normal value as before and after the period of Maunder minimum.
42. Which of these is the hottest part of the Sun?
(a) Corona.
(b) Chromosphere.
(c) Photosphere.
(d) The fusion core.
43. We know that the Sun’s energy does not result from a chemical burning process because
(a) its luminosity would be much larger.
(b) the Sun would have burned up already.
(c) there would be more carbon in its atmosphere.
(d) there is not enough oxygen in its atmosphere.
44. The “Solar Neutrino Problem” refers to the period before 2000s when
(a) fewer electron neutrinos (νe ) were detected than what was predicted by the theory.
(b) more electron neutrinos (νe ) were detected than what was predicted by the theory.
(c) no electron neutrinos (νe ) were detected.
45. The information about the density and temperature profiles within the Sun is obtained
by analyzing
(a) the solar wind.
(b) the solar neutrinos.
(c) the number of sunspots.
(d) the waves on the surface of the Sun.
8
Course: ASTR1P01
Date: December 5, 2014
page 9 of 17 pages
46. The layer of the Sun that we normally see is the
(a) corona.
(b) chromosphere.
(c) photosphere.
47. What is the outer atmosphere of the Sun?
(a) Corona.
(b) Chromosphere.
(c) Photosphere.
48. Which one of these has the lowest density?
(a) Corona.
(b) Chromosphere.
(c) Photosphere.
49. Who was the first to observe the sunspots?
(a) Brahe.
(b) Kepler.
(c) Galileo.
(d) Newton.
(e) [None of the above.]
50. What is the thinest layer of the Sun?
(a) The photosphere.
(b) The convection zone.
(c) The radiation zone.
(d) The fusion core.
51. On average the magnetic field of the Sun reverses its direction every
(a) 11 years.
(b) 22 years.
9
Course: ASTR1P01
Date: December 5, 2014
page 10 of 17 pages
52. Which of these telescopes has the highest light gathering power?
(a)
(b)
(c)
(d)
The
The
The
The
Keck 1 telescope with the objective of 10 m in diameter.
Hubble Space Telescope with the objective of 2.4 m in diameter.
Gemini North telescope with the objective of 8.1 m in diameter.
Hale telescope with the objective of 5.08 m in diameter.
53. Which of these telescopes has the highest resolving power?
(a)
(b)
(c)
(d)
The
The
The
The
Keck 1 telescope with the objective of 10 m in diameter.
Hubble Space Telescope with the objective of 2.4 m in diameter.
Gemini North telescope with the objective of 8.1 m in diameter.
Hale telescope with the objective of 5.08 m in diameter.
54. The light gathering power of the Keck 1 telescope with 10 m objective is about
that of Hale telescope with 5.08 m objective.
(a)
(b)
(c)
(d)
twice
one half
four times
one quarter
55. As the magnification of a telescope increases the brightness of the image
(a) increases.
(b) decreases.
(c) remains unchanged
56. The focal length of the objective mirror of the Hubble Space Telescope is about 58 m.
Which of these eyepieces would give a magnification of 100?
(a)
(b)
(c)
(d)
(e)
An
An
An
An
An
eyepiece
eyepiece
eyepiece
eyepiece
eyepiece
with
with
with
with
with
the
the
the
the
the
focal
focal
focal
focal
focal
length
length
length
length
length
of
of
of
of
of
5.8 m.
58 cm.
5.8 cm
58 mm.
5.8 mm.
57. To detect the X-rays coming from the outer space the X-ray detectors must be placed
in a satellite above the Earth’s atmosphere.
(a) True.
(b) False.
10
Course: ASTR1P01
Date: December 5, 2014
page 11 of 17 pages
58. Which radiation has the shortest wavelength?
(a) Yellow light.
(b) Microwaves.
(c) Red light.
(d) Ultraviolet radiation.
59. Which radiation has the longest wavelength?
(a) Yellow light.
(b) Microwaves.
(c) Red light.
(d) Ultraviolet radiation.
60. Which photon carries the lowest energy?
(a) Yellow light.
(b) Microwaves.
(c) Red light.
(d) Ultraviolet radiation.
61. Which photon carries the highest energy?
(a) Yellow light.
(b) Microwaves.
(c) Red light.
(d) Ultraviolet radiation.
62. A telescope that has a mirror as the objective gathers light by
(a) refraction.
(b) diffraction.
(c) reflection.
(d) dispersion.
63. The speed of light in a more dense medium is greater than the speed of light in a less
dense medium.
(a) True.
(b) False.
11
Course: ASTR1P01
Date: December 5, 2014
page 12 of 17 pages
64. Who was the first to study the night sky with a telescope and report the observations?
(a) Brahe.
(b) Kepler.
(c) Copernicus.
(d) Galileo.
65. The mass of Jupiter is about 300 times larger than the mass of the Earth and its distance
from the Sun is about 5 times larger than the distance of the Earth from the Sun. The
than the force of gravity
force of gravity on Jupiter exerted by the Sun is about
on Earth exerted by the Sun.
(a) 300 times larger
(b) 25 times smaller
(c) 12 times larger
(d) 12 times smaller
66. Who was the first to determine the value of gravitational constant G?
(a) Kepler.
(b) Galileo.
(c) Newton.
(d) Cavendish.
67. It is possible to determine the mass of a planet from the orbital data (the period and
the orbital radius) of one of its satellites.
(a) True.
(b) False.
68. Use the third Kepler’s law to deduce which planet has the longest orbital period (i.e. year).
(a) Venus.
(b) Mars.
(c) Jupiter.
(d) Neptune.
69. The orbital speed of the Earth is greatest when it is at the largest distance from the
Sun.
(a) True.
(b) False.
12
Course: ASTR1P01
Date: December 5, 2015
page 13 of 17 pages
70. The Copernican model explained retrograde motion of planets as a result of
(a) their motion along epicycles.
(b) difference in speeds of the Earth and another planet in their orbits around the Sun.
(c) planets stopping their eastward motion , moving westward awhile, and then resuming their eastward motion.
(d) [None of the above.]
71. At the time of Copernicus, the fact that parallax shift of the brighter stars could NOT
be seen was considered evidence for which model?
(a) The heliocentric model.
(b) The geocentric model.
72. Galileo’s observation of the gibbous and the quarter phases of Venus supported
(a) the heliocentric model.
(b) the geocentric model.
73. With a telescope which has Newtonian focal arrangement the viewing is done from
(a) behind the objective.
(b) the side of the telescope.
(c) inside the telescope.
74. How did Aristarchus deduce that the Sun is at a much greater distance than the Moon?
(a) From the length of the shadow of an obelisk.
(b) From the difference in their angular sizes.
(c) From the elevation of the Moon above the ecliptic.
(d) By comparing the intervals of time between two quarter phases of the Moon.
75. An observer who sees a partial solar eclipse is located in
(a) Moon’s umbra.
(b) Moon’s penumbra.
(c) Earth’s umbra.
(d) Earth’s penumbra.
13
Course: ASTR1P01
Date: December 5, 2014
page 14 of 17 pages
76. An observer who sees a total solar eclipse is located in
(a) Moon’s umbra.
(b) Moon’s penumbra.
(c) Earth’s umbra.
(d) Earth’s penumbra.
77. If the Moon’s orbit was in the plane of the ecliptic, i.e. in the plane of the Earth’s orbit
around the Sun,
(a) we would observe eclipses as often as we do now.
(b) we would observe the solar and the lunar eclipse once a month.
(c) we would never observe eclipses.
(d) we would observe eclipses occasionally, but less often than now.
78. If a star rises tonight at 9:00 pm, yesterday it rose at about
(a) 9:00 pm.
(b) 8:56 pm.
(c) 9:04 pm.
79. Relative to the stars the Sun moves
(a) eastward.
(b) westward.
80. As seen from Ontario in December the Sun sets
(a) north of west.
(b) south of west.
(c) directly west.
81. As seen from the Earth’s North Pole
(a) all stars are circumpolar stars.
(b) no star is a circumpolar star.
(c) some stars are circumpolar and some stars rise and set on the horizon.
14
Course: ASTR1P01
Date: December 5, 2014
page 15 of 17 pages
82. The full moon rises at
(a) sunrise.
(b) noon.
(c) sunset.
(d) midnight.
83. On December 21, 2014, the number of hours of daylight at the latitude 75◦ North will
be
(a) 0.
(b) 12.
(c) 24.
84. The full moon sets at
(a) sunrise.
(b) noon.
(c) sunset.
(d) midnight.
85. The third quarter moon rises at
(a) sunrise.
(b) noon.
(c) sunset.
(d) midnight.
86. The third quarter moon sets at
(a) sunrise.
(b) noon.
(c) sunset.
(d) midnight.
87. The phase of the Moon between the third quarter and the new moon is called
(a) waning crescent.
(b) waxing crescent.
15
Course: ASTR1P01
Date: December 5, 2014
page 16 of 17 pages
88. On the first day of Fall, the Sun sets
(a) North of West.
(b) directly west.
(c) South of West.
89. One can observe the first quarter moon at sunrise.
(a) True.
(b) False.
90. Tomorrow, December 6, is the full Moon. On what day (approximately) will it be new?
(a) December 13.
(b) December 21.
91. As seen from Ontario on summer solstice the Sun is
(a) above celestial equator.
(b) below celestial equator.
(c) on celestial equator.
92. As seen from Ontario on Vernal equinox the Sun is
(a) above celestial equator.
(b) below celestial equator.
(c) on celestial equator.
93. You can observe the waning gibbous moon at sunset.
(a) True.
(b) False.
94. Who collected the accurate data on planetary orbits?
(a) Aristotle.
(b) Brahe.
(c) Copernicus.
(d) Galileo.
16
Course: ASTR1P01
Date: December 5, 2014
page 17 of 17 pages
95. Suppose that you are not very familiar with the stars and constellations, but you notice
that the circumpolar stars which you observe move clockwise. Then you must be located
in the
(a) northern hemisphere.
(b) southern hemisphere.
96. The dates of the eclipses shift from year to year because of the precession of the Earth’s
rotational axis.
(a) True.
(b) False.
97. If the Earth was rotating (spinning) from East to West as observed from above the North
Pole, the stars and the Sun would rise in the West and set in the East.
(a) True.
(b) False.
98. The angular displacement of stars resulting from their annual motion, i.e. because of the
Earth’s revolution around the Sun, is about
(a)
(b)
(c)
(d)
1◦
1◦
1◦
1◦
per
per
per
per
hour.
day.
year.
century.
99. The Andromeda Galaxy 2.5 million light years away is the most distant object easily
seen by the unaided eye. How long does it take light produced by its stars to reach the
Earth.
(a)
(b)
(c)
(d)
2.5 years.
2,500 years.
2.5 million years.
25 million years.
100. Which of the following observations by Galileo was the strongest evidence for heliocentric
model?
(a)
(b)
(c)
(d)
The moons of Jupiter.
Stellar parallax.
The sunspots.
The gibbous and the quarter phases of Venus.
17