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BROCK UNIVERSITY
Number of pages: 17
Number of Students: 500
Number of hours: 2
Instructor: B.Mitrović
Final Exam June 2014
Course: ASTR 1P01
Date of Examination: June 13, 2014
Time of Examination: 9:00–11:00
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. Red giants are stars that are
(a) bright and hot.
(b) bright and cool.
(c) dim and hot.
(d) dim and cool.
2. White dwarfs are stars that are
(a) bright and hot.
(b) bright and cool.
(c) dim and hot.
(d) dim and cool.
3. The binary star systems are important because they are used to determine
(a) the spectral classes of stars.
(b) the distances to stars.
(c) the luminosity classes of stars.
(d) the masses of stars.
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4. What percentage of the known stars are the main sequence stars?
(a)
(b)
(c)
(d)
About 1%.
About 10%.
About 50%.
[None of the above.]
5. The spectroscopic parallax is a method of determining
(a)
(b)
(c)
(d)
a
a
a
a
star’s
star’s
star’s
star’s
spectral class.
luminosity class.
distance from parallax angle.
distance using H-R diagram.
6. Eddington’s mass-luminosity relation is valid for red giants.
(a) True.
(b) False.
For Questions 7-16 refer to Figure 1.
Figure 1
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7. The Sun is represented in the diagram by
(a) S1 .
(b) S2 .
(c) S3 .
(d) S4 .
8. The main sequence star with the smallest mass is
(a) S1 .
(b) S2 .
(c) S3 .
(d) S4 .
9. Among the main sequence stars, the one that is expected to live for the shortest period
of time is
(a) S1 .
(b) S2 .
(c) S3 .
(d) S4 .
10. Which of the following stars is a red supergiant?
(a) S4 .
(b) S5 .
(c) S6 .
(d) S7 .
11. Stars S1 and S6 have the same temperature, but star S6 is more luminous than star S1
because
(a) it has a larger radius.
(b) it has a smaller radius.
(c) it is a main sequence star.
(d) it is closer.
12. Comparing stars S2 and S3 , which one is expected to live longer?
(a) S2 .
(b) S3 .
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13. Which of the following stars is a white dwarf?
(a) S1 .
(b) S6 .
(c) S7 .
(d) [None of the above.]
14. Comparing stars S4 and S6 , which one has the smaller radius?
(a) S4 .
(b) S6 .
15. Which of the following stars is a main sequence star?
(a) S1 .
(b) S5 .
(c) S6 .
(d) S7 .
16. Which of the following stars has the largest mass?
(a) S4
(b) S5
(c) S6
(d) S7
17. Stars on the main sequence that have a large mass are
(a) dim and hot.
(b) dim and cool.
(c) bright and cool.
(d) bright and hot.
18. A star’s distance can be determined using its spectral class and its luminosity class.
(a) True.
(b) False.
19. Red giants have much higher average densities than the white dwarfs.
(a) True.
(b) False.
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20. Which of the following stars has the coolest surface?
(a) K.
(b) G.
(c) B.
(d) F.
21. The spectral lines of a receding star are
(a) blueshifted.
(b) redshifted.
(c) broadened.
(d) narrowed.
22. Which of the following stars has the hottest surface?
(a) Blue.
(b) Yellow.
(c) Red.
23. A star that is hot and dim must have
(a) a very great distance.
(b) a very small mass.
(c) a very small radius.
(d) a very large radius.
24. Stars with masses in excess of 50 solar masses are not very common.
(a) True.
(b) False.
25. The spectroscopic binaries are detected
(a) using spectroscopic parallax.
(b) based on their luminosity class.
(c) as separate stars in telescopic view.
(d) [None of the above.]
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26. Typical sizes of main sequence stars (in units of solar radius R⊙ ) are
(a) from 0.01 R⊙ to 0.1 R⊙ .
(b) from 100 R⊙ to 1000 R⊙ .
(c) from 10 R⊙ to 100 R⊙ .
(d) [None of the above.]
27. When a star’s light passes through its cooler atmosphere
(a) new spectral lines appear in the spectrum.
(b) photons of certain wavelengths are absorbed.
(c) it is redshifted.
(d) it is blueshifted.
28. What is the second most abundant chemical element in the main sequence stars?
(a) Oxygen (O).
(b) Hydrogen (H).
(c) Carbon (C).
(d) Helium (He)
29. To determine the luminosity of a star we need to measure its
(a) brightness and temperature.
(b) brightness and distance.
(c) temperature and distance.
(d) mass and distance.
30. The cooler the star, the shorter is the wavelength of light at which it emits maximum
energy.
(a) True.
(b) False.
31. To determine a star’s radius, we need its
(a) distance and luminosity.
(b) distance and mass.
(c) distance and temperature.
(d) [None of the above.]
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32. The parallax angle for Altair is 0.2 second of arc. Its distance from us in light years is
about
(a) 5.
(b) 16.
(c) 160.
33. The closer the star, the larger its parallax angle.
(a) True.
(b) False.
34. Stars U and W have the same luminosity and star U is ten times more distant than star
W. The brightness of U is
that of W.
(a) 1/10
(b) 1/100
(c) 100 times
(d) 10 times
35. Stars S and U are equally bright and the luminosity of S is four times larger than the
that of U.
luminosity of U. Then the distance of S is
(a) 1/2
(b) 1/4
(c) 4 times
(d) twice
36. The Doppler effect is
(a) the change in the observed brightness of a star when it is moving relative to us.
(b) the change in the observed wavelength/frequency of light when the light source is
moving relative to the observer.
(c) the change in the observed luminosity of a star when it is moving relative to us.
37. Which part of the Sun’s atmosphere has higher temperature?
(a) Chromosphere.
(b) Corona.
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38. The surface temperature of the Sun is determined from
(a) its distance and luminosity.
(b) its distance and brightness.
(c) its spectrum using the Stefan-Boltzmann law.
(d) its spectrum using the Wien’s law.
39. The luminosity of the Sun is determined from
(a) its distance and luminosity.
(b) its distance and brightness.
(c) its spectrum using the Stefan-Boltzmann law.
(d) its spectrum using the Wien’s law.
40. The mass of the Sun is determined from the orbital radius and the orbital period of a
planet using
(a) the first Kepler’s law.
(b) the second Kepler’s law.
(c) the third Kepler’s law as formulated by Newton.
41. The Sun’s distance is 150,000,000 km. How long does it take a radar pulse sent from
the Earth to travel to the Sun and back? The speed of light is 300,000 km/s.
(a) 100 seconds.
(b) 1000 seconds.
(c) 10,000 seconds.
(d) 100,000 seconds.
42. What type of neutrino is produced in proton-proton chain?
(a) Proton neutrino (νp ).
(b) Electron neutrino (νe ).
(c) Muon neutrino (νµ ).
(d) Tau neutrino (ντ ).
43. All of the energy produced in the proton-proton chain is carried by photons (radiation).
(a) True.
(b) False.
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44. The layer of the Sun that we normally see is the
(a) corona.
(b) chromosphere.
(c) ionosphere.
(d) photosphere.
45. The neutrinos interact with other elementary particles via
(a) electrical force.
(b) magnetic force.
(c) strong nuclear force.
(d) weak nuclear force.
46. The solar neutrino problem was resolved by experiments in
(a) Homestake mine.
(b) Sudbury Neutrino Observatory (SNO).
(c) Brookhaven National Laboratory.
(d) Large Hadron Collider.
47. What is the evidence for the convection currents near the Sun’s surface?
(a) Sunspots.
(b) Prominences.
(c) Solar flares.
(d) Granulation of the photosphere.
48. The gamma rays produced in the fusion core leave the Sun as photons in the visible part
of the spectrum because of
(a) the Doppler effect.
(b) the gravitational redshift as they lose energy escaping the Sun’s gravitational pull.
(c) their interaction with the charges in the Sun’s interior.
(d) their interaction with the solar neutrinos.
49. The mass of 4 He is equal to the total mass of four protons that were used to make it in
the fusion reaction.
(a) True.
(b) False.
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50. If the rate of fusion in the core of the Sun spontaneously increased the core would
(a) expand and heat up.
(b) expand and cool down.
(c) contract and heat up.
(d) contract and cool down.
51. What is the second step in the proton-proton chain?
(a) Fusion of two 3 He nuclei into a 4 He nucleus.
(b) Fusion of hydrogen and deuterium into 3 He.
(c) Fusion of two protons into deuterium with a release of a positron, a neutrino and
energy.
(d) [None of the above.]
52. As four protons are replaced by one nucleus of 4 He in the fusion process the core temperain order to maintain the same pressure and keep the Sun in hydrostatic
ture must
equilibrium.
(a) decrease
(b) stay the same
(c) increase
53. The current luminosity of the Sun is the same as it was when it became a main sequence
star.
(a) True.
(b) False.
54. In order to calculate the total number of fusion reactions in the Sun every second one
would need the Sun’s
(a) luminosity and mass.
(b) luminosity and the energy output of a single proton-proton reaction in the form of
radiation.
(c) luminosity and the energy carried by neutrinos that were produced in a single
proton-proton.
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55. Sunspots are areas on the Sun
(a) where the icy comet nuclei struck its surface.
(b) less transparent.
(c) that are cooler.
(d) that are hotter.
56. The first person to observe sunspots through a telescope was
(a) Kepler.
(b) Galileo.
(c) Copernicus.
(d) Brahe.
57. The magnetic field within the sunspot is lower than the Sun’s average magnetic field.
(a) True.
(b) False.
58. The Maunder minimum refers to
(a) the lowest temperature at which hydrogen fusion takes place.
(b) the layer on the Sun’s surface where the temperature is at the minimum.
(c) the minimum lifetime of a main sequence star.
(d) [None of the above.]
59. About how many years elapse between times of maximum solar activity?
(a) 11.
(b) 22.
60. The solar wind is least intense at the times of maximum solar activity.
(a) True.
(b) False.
61. Does the Sun rotate as a solid ball?
(a) No, points near the equator rotate in less time.
(b) No, points near the poles rotate in less time.
(c) Yes, even though it is a gas.
(d) Yes, because it is a solid.
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62. What is approximate length of the Solar magnetic cycle?
(a) About 11 years.
(b) About 22 years.
(c) About 33 years.
63. Which of the following has the lowest density?
(a) Photosphere.
(b) Chromosphere.
(c) Corona.
64. A prominence is
(a) a boundary between the fusion core and the radiation zone.
(b) a boundary between the radiation zone and the convection zone.
(c) a reaction within the Sun’s core.
(d) a huge plume of glowing gas that juts from the lower chromosphere into the corona.
65. What causes aurorae on Earth and some other planets?
(a) X-rays.
(b) Gamma rays.
(c) Cosmic rays.
(d) Solar wind.
66. During a high solar activity there is a higher concentration of
(a) True.
(b) False.
67. Which radiation has the longest wavelength?
(a) Radio waves.
(b) Microwave.
(c) Infrared.
(d) Red.
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68. Which photon carries the lowest energy?
(a) Radio waves.
(b) Microwave.
(c) Infrared.
(d) Red.
69. The largest optical telescopes at present are
(a) reflectors.
(b) refractors.
70. Which one is the most important power of a telescope?
(a) Magnifying.
(b) Light-gathering.
(c) Resolving.
71. The light-gathering power of a 10-inch telescope is
that of a 20-inch telescope.
(a) 1/4
(b) four times
(c) 1/2
(d) twice
72. Which of the following types of radiation from outer space cannot be detected in a
ground-based observatory?
(a) Ultraviolet.
(b) Radio.
(c) X-ray.
73. With a telescope which has Newtonian focal arrangement the viewing is done from
(a) inside the telescope.
(b) behind the objective.
(c) the side of the telescope.
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74. As seen from the Earth’s North Pole
(a) no star is a circumpolar star.
(b) some stars are circumpolar and some stars rise and set on the horizon.
(c) all stars are circumpolar stars.
75. The celestial equator is
(a) the projection of the Earth’s orbit on the celestial sphere.
(b) the projection of the Earth’s equator on the celestial sphere.
(c) the Sun’s apparent path among the stars.
(d) [None of the above.]
76. If a star rises tonight at 10:00 pm, yesterday it rose at about
(a) 10:00 pm.
(b) 9:56 pm.
(c) 10:04 pm.
77. Relative to the stars the Sun moves
(a) westward.
(b) eastward.
78. As seen from Ontario in June the Sun sets
(a) north of west.
(b) south of west.
(c) directly west.
79. As seen from the Earth’s equator
(a) all stars are circumpolar stars.
(b) some stars are circumpolar stars.
(c) there are no circumpolar stars
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80. At present the brightest star nearest the north celestial pole is
(a) Vega.
(b) Polaris.
(c) Sirius.
(d) Thuban.
81. On June 21, 2014, the number of hours of daylight at the latitude 70◦ South will be
(a) 0.
(b) 12.
(c) 24.
82. The Sun appears to travel south, then north, then south again during the year. The
points.
extreme north and south points of this apparent journey are called
(a) solstice
(b) nodal
(c) crossing
(d) equinox
83. The four seasons, Fall, Winter, Spring and Summer, are caused by
(a) changing temperatures of the Sun.
◦
(b) the 23 12 tilt of the Earth’s axis.
(c) slow precession of the Earth’s axis.
(d) sunspot cycle.
84. On the first day of Spring, the Sun rises
(a) North of East.
(b) directly East.
(c) South of East.
85. The phase of the Moon between the new moon and the first quarter is called
(a) waning crescent.
(b) waxing crescent.
86. One can see the third quarter moon at sunset.
(a) True.
(b) False.
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87. Yesterday, June 12, was the full moon. On what day (approximately) will it be new?
(a) June 19.
(b) June 27.
88. The full moon sets at
(a) midnight.
(b) sunrise.
(c) noon.
(d) sunset.
89. The first quarter moon rises at
(a) midnight.
(b) sunrise.
(c) noon.
(d) sunset.
90. You can observe the waxing gibbous moon at sunrise.
(a) True.
(b) False.
91. Who was the first to determine the circumference/radius of the Earth?
(a) Aristotle.
(b) Aristarchus.
(c) Eratosthenes.
(d) Ptolemy.
92. The first Kepler’s law is a statement about
(a) the shape of planetary orbits.
(b) the variation in the speed of a planet as it orbits the Sun.
93. The lunar phase at a lunar eclipse is
(a) full moon.
(b) new moon.
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94. The lunar phase at a solar eclipse is
(a) full moon.
(b) new moon.
95. Which of the following was a valid argument against the heliocentric model of Aristarchus
and later Copernicus?
(a) The Earth would lose its Moon if it was revolving around the Sun.
(b) The heliocentric model contradicted the ideas of Aristotle.
(c) Things would fall off the Earth if it was moving.
(d) Stellar parallax was not observed.
96. A planet moves fastest when it is closest to the Sun
(a) True.
(b) False.
97. Which of the following astronomers found the exact shape of the planetary orbits?
(a) Copernicus.
(b) Kepler.
98. Which of the following astronomers found that gravity is responsible for keeping the
Moon in its orbit around the Earth?
(a) Newton.
(b) Kepler.
99. Which of the following observations by Galileo was the strongest evidence for heliocentric
model?
(a) The moons of Jupiter.
(b) Stellar parallax.
(c) The sunspots.
(d) The gibbous and the quarter phases of Venus.
100. Why are the positrons produced in fusion of two protons into a nucleus of deuterium
2
H?
(a) To balance the mass.
(b) To balance the electric charge.
(c) To balance the number of particles.
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