ASTRO 1 FINAL EXAM PSU SCRIPT
QUESTIONS WITH 100% CORRECT
ANSWERS +
⩥ In the present stage of the Sun's lifetime, it is converting hydrogen
into helium in its core. The total lifetime of this stage, from when the
Sun first formed until it exhausts the supply of hydrogen in its core, is
calculated to be
A. approximately 10 billion (1010) years.
B. almost 200 billion (2 × 1011) years.
C. approximately 5 million (5 × 106) years.
D. slightly more than 10,000 (104) years. Answer: A
⩥ A difficulty in attributing the energy source of the Sun to anything but
nuclear reactions is
A. a lack of alternate ideas.
B. a lack of other reasonable sources of fuel.
C. that reliance on other sources of energy requires the Sun to be
unreasonably young.
D. that other sources of energy do not work in the vacuum of space.
Answer: C
,⩥ Why do nuclear fusion reactions, like those in the Sun, take place only
at high temperatures?
A. The high temperatures are a result of the energy released in the
reactions. They are not actually needed to produce the reactions.
B. The high temperatures are needed to ionize the atoms (to strip them
of their electrons) so that the bare nuclei can interact.
C. All nuclei are positive, and high temperatures—and the high
velocities that go with them—are necessary to force these repulsive
nuclei together.
D. To undergo fusion reactions, a nucleus must separate into its
constituent particles (neutrons and protons), and this happens only at
high temperatures. Answer: C
⩥ Hydrostatic equilibrium tells us that
A. the force of gas pressure outward is balanced by the pull of gravity
inward.
B. convectively moving gas is always replaced by an equal amount of
fresh gas.
C. the energy produced in the core of the Sun is balanced by the flow of
energy from the Sun's surface into space.
D. the centripetal force outward due to the Sun's rotation is balanced by
the force of gravity inward. Answer: A
⩥ The internal structure of the Sun, in order from the center to the
surface, is
,A. energy-generating core, radiative region, convective region.
photosphere.
B. energy-generating core, photosphere, convective region, radiative
region.
C. convective core, chemically-reacting region, radiative region.
D. Chromosphere, energy-generating core, convective region. Answer:
A
⩥ For many years, neutrino detectors on the Earth detected only about
one-third as many neutrinos from the Sun as was expected from theory.
The reason for this discrepancy was recently proven to be that the
A. neutrinos change from one type to another while in flight.
B. Sun's core is 10% cooler than had earlier been thought.
C. Sun's core contains less hydrogen than had earlier been thought.
D. majority of solar neutrinos pass through the detectors undetected.
Answer: A
⩥ The outer limb of the Sun is darker than the center because
A. we see in to deeper, hotter levels at the limb.
B. we see higher, cooler levels at the limb.
C. the fusion process is weaker at the limb.
D. the photosphere is not as thick at the edge. Answer: B
, ⩥ The granules we see under excellent observing conditions on the
visible surface of the Sun are
A. the tops of columns of rising and falling gas in the layer below the
photosphere.
B. cooler, darker regions where the Sun's magnetic field is particularly
intense.
C. columns of gas rising through the Sun's chromosphere.
D. waves created by oscillations in the solar interior, with periods of
between 5 and 20 minutes. Answer: A
⩥ Which of the following phenomena is not produced by the Sun's
magnetic field?
A. sunspots
B. plages
C. prominences
D. granulation Answer: D
⩥ Why does the light from the chromosphere appear to be pinkish-red?
A. The light from the chromosphere is dominated by photons emitted by
a single red spectral line, Hα, in the Balmer series
of hydrogen.
B. The temperature is lower than in the photosphere, producing a
blackbody spectrum with peak wavelength in the infrared.
C. M
QUESTIONS WITH 100% CORRECT
ANSWERS +
⩥ In the present stage of the Sun's lifetime, it is converting hydrogen
into helium in its core. The total lifetime of this stage, from when the
Sun first formed until it exhausts the supply of hydrogen in its core, is
calculated to be
A. approximately 10 billion (1010) years.
B. almost 200 billion (2 × 1011) years.
C. approximately 5 million (5 × 106) years.
D. slightly more than 10,000 (104) years. Answer: A
⩥ A difficulty in attributing the energy source of the Sun to anything but
nuclear reactions is
A. a lack of alternate ideas.
B. a lack of other reasonable sources of fuel.
C. that reliance on other sources of energy requires the Sun to be
unreasonably young.
D. that other sources of energy do not work in the vacuum of space.
Answer: C
,⩥ Why do nuclear fusion reactions, like those in the Sun, take place only
at high temperatures?
A. The high temperatures are a result of the energy released in the
reactions. They are not actually needed to produce the reactions.
B. The high temperatures are needed to ionize the atoms (to strip them
of their electrons) so that the bare nuclei can interact.
C. All nuclei are positive, and high temperatures—and the high
velocities that go with them—are necessary to force these repulsive
nuclei together.
D. To undergo fusion reactions, a nucleus must separate into its
constituent particles (neutrons and protons), and this happens only at
high temperatures. Answer: C
⩥ Hydrostatic equilibrium tells us that
A. the force of gas pressure outward is balanced by the pull of gravity
inward.
B. convectively moving gas is always replaced by an equal amount of
fresh gas.
C. the energy produced in the core of the Sun is balanced by the flow of
energy from the Sun's surface into space.
D. the centripetal force outward due to the Sun's rotation is balanced by
the force of gravity inward. Answer: A
⩥ The internal structure of the Sun, in order from the center to the
surface, is
,A. energy-generating core, radiative region, convective region.
photosphere.
B. energy-generating core, photosphere, convective region, radiative
region.
C. convective core, chemically-reacting region, radiative region.
D. Chromosphere, energy-generating core, convective region. Answer:
A
⩥ For many years, neutrino detectors on the Earth detected only about
one-third as many neutrinos from the Sun as was expected from theory.
The reason for this discrepancy was recently proven to be that the
A. neutrinos change from one type to another while in flight.
B. Sun's core is 10% cooler than had earlier been thought.
C. Sun's core contains less hydrogen than had earlier been thought.
D. majority of solar neutrinos pass through the detectors undetected.
Answer: A
⩥ The outer limb of the Sun is darker than the center because
A. we see in to deeper, hotter levels at the limb.
B. we see higher, cooler levels at the limb.
C. the fusion process is weaker at the limb.
D. the photosphere is not as thick at the edge. Answer: B
, ⩥ The granules we see under excellent observing conditions on the
visible surface of the Sun are
A. the tops of columns of rising and falling gas in the layer below the
photosphere.
B. cooler, darker regions where the Sun's magnetic field is particularly
intense.
C. columns of gas rising through the Sun's chromosphere.
D. waves created by oscillations in the solar interior, with periods of
between 5 and 20 minutes. Answer: A
⩥ Which of the following phenomena is not produced by the Sun's
magnetic field?
A. sunspots
B. plages
C. prominences
D. granulation Answer: D
⩥ Why does the light from the chromosphere appear to be pinkish-red?
A. The light from the chromosphere is dominated by photons emitted by
a single red spectral line, Hα, in the Balmer series
of hydrogen.
B. The temperature is lower than in the photosphere, producing a
blackbody spectrum with peak wavelength in the infrared.
C. M
