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Review
Astronomy 101, Exam #2
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No notes, No books; You can use calculators
c = 3 x 108 m/s
1 AU = 1.49 ×1011 meters
1 light year = 9.46 × 1015 meters
h = 6.626 x 10-34 J●s
G = 6.67 × 10-11 m3 kg-1 s-2
g = 9.8 m/s2
σ = 5.67 x 10-8 W m-2 K-4
mass of Earth = 5.97 × 1024 kg
mass of Moon = 7.35 x 1022 kg
radius of Earth = 6.38 × 106 m
1 nm = 1 x 10-9 meters
mass of Sun = 1.99 x 1030 kg
mass of Jupiter = 1.90 x 1027 kg
radius of Jupiter = 7.15 × 107 m
radius of Moon = 1.74 × 106 m
1) Why were the first images from the Hubble Space Telescope blurry?
A)
B)
C)
D)
E)
The gyroscopes were faulty.
The mirror was too flat at the edges.
The lenses were too thick.
The telescope was too hot.
The telescope was too heavy.
2) If it is 400o Celsius, what is the temperature in Kelvin?
A)
B)
C)
D)
E)
27.15 Kelvin
136.85 Kelvin
573.15 Kelvin
883.15 Kelvin
673.15 Kelvin
3) From a measurement in the laboratory, we know that a particular spectral line
formed by hydrogen appears at a wavelength of 486.1 nm. The spectrum of a
particular star shows the same hydrogen line appearing at a wavelength of 485.7
nm. What can we conclude from this observation?
A) The star is getting hotter.
B) The star must be very distant.
C) The star is getting colder.
D) The star is moving away from us.
E) The star is moving toward us.
Astronomy 101, Exam #2
Review
4) An infrared photon has a frequency of 1 x 1013 Hz. What is the wavelength of
this photon?
A)
B)
C)
D)
E)
3 x 10-5 meters
6.626 x 10-21 meters
3 x 108 meters
6.626 x 10-6 meters
3 x 1021 meters
5) As the wavelengths of photons of light increase, their …
A)
B)
C)
D)
E)
Frequencies increase and their energies increase
Frequencies decrease and their energies increase
Frequencies decrease and their energies decrease
Frequencies increase and their energies stay the same
Frequencies stay the same and their energies stay the same
6) Which of the following objects has the most kinetic energy?
A) A 10 kg mass moving at 1 km/s.
B) A 2 kg mass moving at 2 km/s.
C) A 2 kg mass moving at 5 km/s.
D) A 5 kg mass moving at 2 km/s.
E) A 3 kg mass moving at 3 km/s.
7) Why was the newly discovered ring around Saturn discovered with a satellite that
could measure infrared light and not with a satellite that could measure visible light?
A) no satellites that could measure visible light are currently in space
B) the particles in the rings are so cold that they are brighter in the infrared
than in the visible
C) visible light can’t penetrate the Earth’s atmosphere
D) visible light can’t travel through dust
E) infrared light has a much longer frequency than visible light so it is easier to
detect in space
Astronomy 101, Exam #2
Review
8) You heat a black ball from a temperature of 400 Kelvin to a temperature of 800 Kelvin.
Which of these statements is true?
A)
B)
C)
D)
E)
Twice as much energy per second is emitted by the hotter body.
Four times as much energy per second is emitted by the hotter body.
Eight times as much energy per second is emitted by the hotter body.
Sixteen times as much energy per second is emitted by the hotter body.
Three hundred times as much energy per second is emitted by the hotter body.
9) The nucleus of an atom may contain …
A) neutrons and electrons.
B) protons and neutrons.
C) ions.
D) protons and electrons.
E) neutrinos and electrons
10) What is the frequency of a photon of light if the wavelength is 1 x 105 meters?
1 x 1016 Hertz
3 x 1016 Hertz
3 x 1013 Hertz
9 x 1010 Hertz
3 x 103 Hertz
A)
B)
C)
D)
E)
11) Kinetic energy is usually given in units of …
A)
B)
C)
D)
E)
Newtons
Joules
Kilograms
Hertz
Gauss
12) You take an image of the sky. On the image, a star has an apparent magnitude of +8,
a main-belt asteroid has an apparent magnitude of +6, a Kuiper Belt Object has an
apparent magnitude of +17, a Trojan asteroid has an apparent magnitude of +14, and
Pluto has an apparent magnitude of +15. Which object is brightest in the sky?
A)
B)
C)
D)
E)
The star
The main-belt asteroid
The Kuiper Belt Object
The Trojan asteroid
Pluto
Astronomy 101, Exam #2
Review
13) Which is not a real advantage of a space-based telescope compared to an Earth-based
telescope?
A) It can be open 24 hours and 7 days of week
B) The space-based telescope is closer to the objects it studies.
C) You do not have to worry about distorting effects of atmosphere
D) There is no extra background of light due to scattering of light in the Earth’s
atmosphere.
E) You can observe in more wavelength regions
14) Why are gamma-ray telescopes located in space and not on the surface of the Earth?
A)
B)
C)
D)
E)
Gamma rays are dangerous to humans.
Gamma rays cannot penetrate the Earth’s atmosphere
Gamma rays tend to make the telescope radioactive
Gamma rays penetrate deep into the ground
Gamma rays do not interact with silicon properly on the surface of the Earth
15) Somebody says that a spectrum of a star appears redshifted. What is happening to the
star?
A)
B)
C)
D)
E)
The star is getting hotter
The star is getting colder
The star is moving towards you.
The star is moving away from you
The star is getting larger
16) A star is 10 light years from Earth. The star is moved so it is 5 light years from Earth.
How will the apparent brightness of the star change?
A)
B)
C)
D)
E)
The apparent brightness will not change
The apparent brightness will become twice as bright.
The apparent brightness will become four times as bright
The apparent brightness will become eight times as bright.
The apparent brightness will become sixteen times as bright.
17) Different elements always have different numbers of …
A)
B)
C)
D)
E)
Neutrons
Protons
Isotopes
Neurons
Neutrinos
Astronomy 101, Exam #2
18) One gram of uranium is completely turned into energy.
produced?
A)
B)
C)
D)
E)
Review
How much energy is
9 x 1016 Joules
3 x 1016 Joules
9 x 1013 Joules
3 x 1016 Joules
1 x 1016 Joules
19) Put these parts of the electromagnetic spectrum in order from shortest wavelength to
longest wavelength:
Shortest  Longest wavelength
A)
B)
C)
D)
E)
Gamma-ray, X-ray, ultraviolet, infrared, visible, radio
Gamma-ray, X-ray, ultraviolet, visible, infrared, radio
X-ray, gamma-ray, ultraviolet, visible, infrared, radio
Radio, gamma-ray, X-ray, ultraviolet, visible, infrared
Radio, infrared, visible, ultraviolet, X-ray, Gamma-ray
20) Put these parts of the electromagnetic spectrum in order from lowest frequency to
highest frequency:
Lowest  Highest frequency
A)
B)
C)
D)
E)
Radio, infrared, visible, ultraviolet, X-ray, gamma-ray
Gamma-ray, X-ray, ultraviolet, visible, infrared, radio
Radio, visible, ultraviolet, X-ray, gamma-ray, infrared
Gamma-ray, X-ray, ultraviolet, visible, radio, infrared
Radio, X-ray, infrared, ultraviolet, visible, gamma-ray
21) Put these parts of the electromagnetic spectrum in order from lowest energy to
highest energy:
Lowest  Highest energy
A)
B)
C)
D)
E)
Gamma-ray, X-ray, ultraviolet, infrared, visible, radio
Gamma-ray, X-ray, ultraviolet, visible, infrared, radio
X-ray, gamma-ray, ultraviolet, visible, infrared, radio
Radio, gamma-ray, X-ray, ultraviolet, visible, infrared
Radio, infrared, visible, ultraviolet, X-ray, Gamma-ray
Astronomy 101, Exam #2
Review
22) As the temperature decreases for an object, the peak of the black-body radiation
curve measured for the object moves to …
A)
B)
C)
D)
E)
lower intensities and longer wavelengths
higher intensities and shorter wavelengths
lower intensities and shorter wavelengths
higher intensities and longer wavelengths
does not change in intensity or in wavelength position
23) What is a CCD (which stands for charge-coupled device) used for?
A) It is the world's largest operating telescope.
B) It refers to any kind of instrument that can be hooked up to a telescope.
C) It is an electronic detector that can be used in place of photographic film for
taking images of the sky.
D) It is a unit used by astronomers to measure angular resolution.
E) It is the next telescope that will be launched into space.
24) Which is not a reason why all large modern telescopes tend to be reflectors?
A) It is much easier to make a high-quality mirror than the same quality lens
B) Large mirrors are much lighter than large lenses
C) Lenses focus different wavelengths of light slightly differently. Mirrors do
not have this problem
D) Some wavelengths of light can be significantly absorbed by the lens.
E) Lenses cannot be used to observe astronomical objects.
25) Which is not a phase of matter?
A) gas
B) solid
C) liquid
D) psion
E) plasma
26) The temperature in this room is closest to what temperature in Kelvin?
A)
B)
C)
D)
E)
100 Kelvin
200 Kelvin
300 Kelvin
400 Kelvin
500 Kelvin
Astronomy 101, Exam #2
Review
27) A prism can be used to break light up into its constituent spectral colors since
different wavelengths of light are refracted differently by glass and leave the prism at
different angles. What is the order of the colors of light from shortest to longest
wavelength?
Shortest  Longest wavelength
A)
B)
C)
D)
E)
Violet, Indigo, Red, Blue, Green, Yellow, Orange
Red, Orange, Yellow, Green, Blue, Indigo, Violet
Red, Yellow, Orange, Blue, Green, Indigo, Violet
Violet, Indigo, Green, Blue, Orange, Yellow, Red
Violet, Indigo, Blue, Green, Yellow, Orange, Red
28) Light can act as which of the following?
A)
B)
C)
D)
E)
Only as a particle
Only as an isotope
Only as a wave
As a particle and a wave
Only as an ion
29) Who was the first to propose the formula E=mc2 for converting matter into energy?
A) Isaac Newton
B) Albert Einstein
C) Henry Cavendish
D) Tycho Brahe
E) Johannes Kepler
30) Which of these particles take the shortest time to travel from the core of the Sun to
the surface of the Sun?
A)
B)
C)
D)
E)
gamma ray photon
positron
neutrino
electron
proton
31) The two most abundant elements in the Sun are?
A) oxygen and carbon.
B) iron and hydrogen.
C) carbon and iron.
D) hydrogen and helium.
E) iron and helium.
Astronomy 101, Exam #2
Review
32) Which star is closest in distance to the Earth?
A)
B)
C)
D)
E)
Alpha Centauri A
Sirius
Sun
Polaris
Proxima
33) The Hertzsprung-Russell Diagram has ________________.
(the horizontal axis is the x-axis and the vertical axis is the y-axis)
A) surface temperature (or spectral type) on its horizontal axis and apparent
brightness on its vertical axis
B) age on its horizontal axis and diameter on its vertical axis
C) surface temperature (or spectral type) on its horizontal axis and stellar
luminosity on its vertical axis
D) diameter on its horizontal axis and lifetime on its vertical axis
E) diameter on its horizontal axis and stellar luminosity on its vertical axis
34) Which of these spectral types has the hottest surface temperature?
A) B type
B) F type
C) G type
D) K type
E) M type
35) How was the Homestake Gold Mine used to detect neutrinos?
A) The Gold in the mine tends to react with the neutrinos and become radioactive.
This radioactivity could be measured
B) The mine contains water that undergoes fusion when neutrinos strike it. The
resulting heat could be measured
C) The mine was filled with a chlorine-containing liquid. When a Chlorine atom
captures a neutrino, it becomes radioactive argon, which releases an electron
which can be detected by a detector.
D) The mine was filled with Argon gas. When an Argon atom captures a neutrino,
it becomes radioactive Krypton, which releases an electron which can be detected
by a detector.
E) The Gold in the mine tends to slow the neutrinos down and allows them to be
detected by a neutrino detector.
Astronomy 101, Exam #2
Review
36) The Sun produces energy by the fusion of 4 hydrogen atoms into 1 helium atom. The
amount of energy produced can be computed from the equation that relates energy
and mass: E = mc2. To compute the energy generated by the fusion of 4 hydrogen
atoms, the m in this equation should be
A) the mass of the 4 hydrogen atoms.
B) the mass of the 1 helium atom.
C) the mass of just 1 hydrogen atom.
D) the sum of the masses of the 4 hydrogen atoms and the 1 helium atom.
E) the difference in mass between the 4 hydrogen atoms and the 1 helium atom.
37) Main sequence stars tend to have this trait in common with each other.
A) They all tend to fuse Hydrogen into Helium
B) They all tend to have similar diameters.
C) They all tend to have similar temperatures.
D) They all tend to have similar masses.
E) They all tend to fuse Helium into Carbon.
38) What is the complete stellar classification of the Sun?
A)
B)
C)
D)
E)
M5 V
M2 I
G2 V
B4 V
K3 III
Use Table 1 for questions 39, 40, and 41
Table 1. Here are some stars and their spectral classification
Star
Classification
Sirius A
A1 V
Achernar
B5 V
Aldebaran B
M2 V
Fomalhaut B
K4 V
Betelgeuse
M2 I
39) Which star is not on the Main Sequence?
A)
B)
C)
D)
E)
Sirius A
Achernar
Aldebaran B
Fomalhaut B
Betelgeuse
Astronomy 101, Exam #2
Review
40) Which two stars would you expect to have surface temperatures that are closest in
value to each other?
A)
B)
C)
D)
E)
Sirius A and Achernar
Achernar and Fomalhaut B
Aldebaran B and Betelgeuse
Fomalhaut B and Sirius A
Betelgeuse and Fomalhaut B
41) Which star would you expect to be the smallest in mass?
A)
B)
C)
D)
E)
Sirius A
Achernar
Aldebaran B
Fomalhaut B
Betelgeuse
42) Who first proposed that a star’s surface temperature determines the strength of its
spectral lines?
A)
B)
C)
D)
E)
Edward Pickering
Albert Einstein
Cecilia Payne-Gaposchkin
Marie Curie
Jocelyn Bell
43) For main sequence stars, the general rule is that the higher the surface
temperature, …
A) the more numerous are the stars.
B) the greater the masses of the stars.
C) the less luminous are the stars.
D) the more common are binary stars.
E) the longer the lifetime on the main sequence
44) The process by which two or more smaller nuclei slam together and make a larger
nucleus is called …
A) Nuclear fission
B) Nuclear fusion
C) Strong force
D) Electron decay
E) Gravitational equilibrium
Astronomy 101, Exam #2
Review
45) The total lifetime of the Sun as a main sequence star is approximately
A)
B)
C)
D)
E)
one hundred billion (100,000,000,000) years.
ten million (10,000,000) years.
one million (1,000,000) years.
one hundred million (100,000,000) years.
ten billion (10,000,000,000) years
46) What is the order of the regions of the Sun from the center outward?
A) corona, core, convection zone, radiation zone, photosphere, chromosphere
B) core, radiation zone, convection zone, photosphere, chromosphere, corona
C) photosphere, chromosphere, core, radiation zone, convection zone, corona
D) core, radiation zone, corona, convection zone, chromosphere, photosphere
E) radiation zone, core, convection zone, photosphere, corona, chromosphere
47) Suppose two stars are identical except that one star is four times as far away from us
as the other star. Which statement is true?
A) Both stars have the same luminosity, but the apparent brightness of the closer
star is sixteen times greater than that of the more distant star.
B) Both stars have the same apparent brightness, but the luminosity of the closer
star is sixteen times greater than that of the more distant star.
C) Both stars have the same apparent brightness, but the luminosity of the closer
star is four times greater than that of the more distant star.
D) Since the stars are identical, they have the same apparent brightness and
luminosity.
E) Both stars have the same luminosity, but the apparent brightness of the closer
star is four times greater than that of the more distant star.
48) Where does fusion take place in the Sun during its main sequence lifetime?
A) convection zone.
B) core.
C) corona.
D) photosphere.
E) chromosphere.
49) Which part (or layer) of the Sun has the coldest temperature?
A) core
B) corona
C) chromosphere.
D) photosphere
E) radiation zone