Question 1

The visible corona of the Sun is MOST effectively photographed:

Accepted Answer

A)   during lunar eclipses, when the sky is darker.
B)   during solar eclipses.
C)   over a period of a few years around times of maximum solar activity.
D)   in spring and fall seasons because of the tilt of the spin axis of the Sun.E) B) and D)
F) A) and B)

Question 2

Which body does NOT exhibit some differential rotation?

Accepted Answer

A)   the Moon
B)   the Sun
C)   Jupiter
D)   SaturnE) A) and B)
F) C) and D)

Question 3

The temperature of the Sun throughout its radius and including its atmosphere:

Accepted Answer

A)   is almost constant from the center to the surface but falls abruptly above the visible surface.
B)   decreases outward from the center but then increases again in the atmosphere.
C)   decreases smoothly outward from the center, gradually merging at the "top" of the atmosphere into the cold of the interplanetary medium.
D)   increases and decreases several times between the center and the surface, then decreases through the atmosphere.E) B) and D)
F) B) and C)

Question 4

How does the Sun's overall magnetic field behave?

Accepted Answer

A)   The Sun does not have an overall coherent field but magnetic fields, and their polarity is centered on sunspots and randomly distributed over the Sun.
B)   The northern and southern hemispheres have the same magnetic polarity, which reverses every 11 years.
C)   The northern and southern hemispheres have opposite magnetic polarity, which reverses every 11 years.
D)   The poles of the Sun have the opposite magnetic polarity from the equator, which reverses every 11 years.E) B) and C)
F) C) and D)

Question 5

We have orbiting satellites that continually monitor the Sun.These observations take place in all regions of the electromagnetic spectrum EXCEPT:

Accepted Answer

A)   visible.
B)   radio.
C)   X ray.
D)   ultraviolet.E) A) and B)
F) A) and C)

Question 6

Which statement seems to be the CORRECT explanation for the low neutrino rates detected by Davis and others?

Accepted Answer

A)   The neutrinos oscillate and change their nature en route from the Sun to Earth.
B)   The core of the Sun is actually about 10% cooler than had been originally predicted.
C)   The Davis result was subjected to much uncertainty because it measured only a small-yield side branch of the main nuclear reaction.
D)   The neutrinos Davis detected were coming not from the Sun but instead from sources within Earth.E) A) and B)
F) A) and C)

Question 7

Until recent times,astronomers had to await a total solar eclipse to study the chromosphere.Why do suppose you cannot hold a coin in front of you to cover the solar disk and create an artificial eclipse that will permit you to study the chromosphere?

Accepted Answer

A)   Refraction of light around the coin will cause light from the photosphere to enter your eye along with light from the chromosphere.
B)   Light from the very rarified chromosphere is too weak to penetrate Earth's atmosphere.
C)   Scattering by Earth's atmosphere will allow light from the photosphere to pass around the coin and enter your eye.
D)   Even with electronic equipment, it is not possible to hold the coin steady enough against the apparent motion of the Sun to view only the thin chromosphere.E) A) and B)
F) B) and C)

Question 8

Sunspots are caused by:

Accepted Answer

A)   the impact of meteoroids and comets on the solar surface.
B)   differential rotation and its effect on weak magnetic fields just under the solar surface.
C)   dark, absorbing clouds hanging over the surface, above the magnetic field regions.
D)   coronal holes, which darken the surface.E) A) and B)
F) A) and C)

Question 9

Compared with the photosphere,the solar chromosphere is:

Accepted Answer

A)   less dense but with a greater vertical extent.
B)   cooler and with a greater vertical extent.
C)   denser but with a narrower vertical extent.
D)   hotter and with a narrower vertical extent.E) B) and C)
F) A) and D)

Question 10

What is the reason that the edge of the Sun's visible disk is darker than the center?

Accepted Answer

A)   The gases near the edge are in regions where stronger magnetic fields inhibit the emission of light.
B)   We see more deeply into the Sun near its edge, and the gas is cooler at the deeper levels.
C)   We see into shallower layers of the Sun near the edge, where the gas is cooler and so emits less light.
D)   We see into shallower layers of the Sun near the edge; because the gas is less dense there, it emits less light.E) None of the above
F) C) and D)

Question 11

What is the solar wind?

Accepted Answer

A)   a storm of waves and vortices on the Sun's surface generated by a solar flare
B)   the constant flux of photons from the Sun's visible surface
C)   the circulation of gases between the equator and the poles of the Sun
D)   the Sun's outer atmosphere streaming out into spaceE) All of the above
F) B) and D)

Question 12

Where on the Sun do solar flares occur?

Accepted Answer

A)   only in a narrow band along the solar equator
B)   only at the polar regions
C)   only in coronal holes
D)   only within sunspot groupsE) None of the above
F) All of the above

Question 13

The Sun has existed for a very long time without change in its appearance or behavior,so it must be in hydrostatic equilibrium.Under these conditions,which two parameters must be in balance at all points throughout the Sun's interior?

Accepted Answer

A)   magnetic field and the force of gravity
B)   force of gravity and outward gas pressure
C)   numbers of hydrogen and helium nuclei
D)   hydrogen gas pressure and helium gas pressureE) C) and D)
F) All of the above

Question 14

The energy source that heats the low-density coronal gas to extremely high temperatures is MOST probably:

Accepted Answer

A)   conduction because the chromosphere and corona contain high densities of free electrons that facilitate conduction.
B)   rearrangements within complex magnetic field structures that energize the ionized gas.
C)   convective currents in the chromosphere that carry hot gas outward from the photosphere.
D)   radiative heat from the photosphere that is strongly absorbed by highly ionized atoms such as Fe XIV.E) A) and D)
F) All of the above

Question 15

The gas motions within granules on the solar surface are:

Accepted Answer

A)   upward in the centers of some cells and downward in the centers of others; the gas cools as it passes over the boundaries between cells.
B)   upward in the bright cell centers and downward around the darker edges.
C)   downward in the bright cell centers and upward around the darker edges.
D)   almost nonexistent; the dark patterns represent a network of absorbing gases overlying the photosphere.E) None of the above
F) A) and B)

Question 16

Just outside the radiation zone lies the:

Accepted Answer

A)   convection zone.
B)   conduction zone.
C)   photosphere.
D)   corona.E) B) and C)
F) C) and D)

Question 17

Astronomers use the word "limb" to refer to what part of a celestial body?

Accepted Answer

A)   edge
B)   center
C)   top
D)   bottomE) B) and C)
F) A) and B)

Question 18

The young Sun had a core containing less helium and more hydrogen than it has now.Each of the following is a consequence of this EXCEPT ONE.Which is the exception?

Accepted Answer

A)   less massive
B)   cooler in its core
C)   less luminous
D)   smallerE) C) and D)
F) A) and B)

Question 19

When four protons collide to form helium,what fraction of the original mass of the protons is converted into energy?

Accepted Answer

A)   3/4 of 1%
B)   100%
C)   1/20 of 1%
D)   4%E) None of the above
F) All of the above

Question 20

What is the energy source for the Sun?

Accepted Answer

A)   thermonuclear fusion in the core
B)   radioactive decay of the nuclei of heavy elements
C)   primordial heat, left behind from when the Sun first formed
D)   heat released by gravitational contraction as the Sun slowly shrinksE) A) and B)
F) B) and C)

Exam 9: The Sun: Our Extraordinary Ordinary Star

The Sun has existed for a very long time without change in its appearance or behavior,so it must be in hydrostatic equilibrium.Under these conditions,which two parameters must be in balance at all points throughout the Sun's interior?

Correct AnswerverifiedShow Answer

Where on the Sun do solar flares occur?

Correct AnswerverifiedShow Answer

When four protons collide to form helium,what fraction of the original mass of the protons is converted into energy?

Correct AnswerverifiedShow Answer

The young Sun had a core containing less helium and more hydrogen than it has now.Each of the following is a consequence of this EXCEPT ONE.Which is the exception?

Correct AnswerverifiedShow Answer

Which statement seems to be the CORRECT explanation for the low neutrino rates detected by Davis and others?

Correct AnswerverifiedShow Answer

Which body does NOT exhibit some differential rotation?

Correct AnswerverifiedShow Answer

What is the solar wind?

Correct AnswerverifiedShow Answer

Compared with the photosphere,the solar chromosphere is:

Correct AnswerverifiedShow Answer

Astronomers use the word "limb" to refer to what part of a celestial body?

Correct AnswerverifiedShow Answer

How does the Sun's overall magnetic field behave?

Correct AnswerverifiedShow Answer

The visible corona of the Sun is MOST effectively photographed:

Correct AnswerverifiedShow Answer

Just outside the radiation zone lies the:

Correct AnswerverifiedShow Answer

Sunspots are caused by:

Correct AnswerverifiedShow Answer

The energy source that heats the low-density coronal gas to extremely high temperatures is MOST probably:

Correct AnswerverifiedShow Answer

What is the energy source for the Sun?

Correct AnswerverifiedShow Answer

The temperature of the Sun throughout its radius and including its atmosphere:

Correct AnswerverifiedShow Answer

The gas motions within granules on the solar surface are:

Correct AnswerverifiedShow Answer

We have orbiting satellites that continually monitor the Sun.These observations take place in all regions of the electromagnetic spectrum EXCEPT:

Correct AnswerverifiedShow Answer

What is the reason that the edge of the Sun's visible disk is darker than the center?

Correct AnswerverifiedShow Answer

Until recent times,astronomers had to await a total solar eclipse to study the chromosphere.Why do suppose you cannot hold a coin in front of you to cover the solar disk and create an artificial eclipse that will permit you to study the chromosphere?

Correct AnswerverifiedShow Answer

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