Question 1

In the proton-proton chain

Accepted Answer

A)  no neutrinos are produced. 
B)  energy is released because a helium nucleus has a greater mass than a hydrogen nucleus. 
C)  no photons are produced. 
D)  carbon serves as a catalyst for the nuclear reaction. 
E)  energy is produced in the form of gamma rays and the velocity of the created nuclei. 
A)  no neutrinos are produced. 
B)  energy is released because a helium nucleus has a greater mass than a hydrogen nucleus. 
C)  no photons are produced. 
D)  carbon serves as a catalyst for the nuclear reaction. 
E)  energy is produced in the form of gamma rays and the velocity of the created nuclei.

Question 2

Nuclear fusion in stars is controlled by the dependence of density on mass.

Accepted Answer

A) True 
 B)False

Question 3

The region of the sun just below the photosphere

Accepted Answer

A)  is undergoing thermonuclear fusion using the proton-proton chain. 
B)  is undergoing thermonuclear fusion using the CNO cycle. 
C)  is transporting energy to the photosphere by convection. 
D)  is not in hydrostatic equilibrium. 
E)  a and c above 
A)  is undergoing thermonuclear fusion using the proton-proton chain. 
B)  is undergoing thermonuclear fusion using the CNO cycle. 
C)  is transporting energy to the photosphere by convection. 
D)  is not in hydrostatic equilibrium. 
E)  a and c above

Question 4

The carbon-nitrogen-oxygen cycle

Accepted Answer

A)  operates at a slightly lower temperature than the proton-proton chain. 
B)  is most efficient in a star less massive than the sun. 
C)  occurs when carbon and oxygen combine to form nitrogen,which produces energy. 
D)  produces the energy responsible for bipolar flows. 
E)  combines four hydrogen nuclei to form one helium nucleus,which produces energy. 
A)  operates at a slightly lower temperature than the proton-proton chain. 
B)  is most efficient in a star less massive than the sun. 
C)  occurs when carbon and oxygen combine to form nitrogen,which produces energy. 
D)  produces the energy responsible for bipolar flows. 
E)  combines four hydrogen nuclei to form one helium nucleus,which produces energy.

Question 5

Energy flows by radiation or convection inside stars but almost never by conduction.

Accepted Answer

A) True 
 B)False

Question 6

The youngest stars in the Orion Nebula and other star-forming regions also show

Accepted Answer

A)  circumstellar disks 
B)  jets 
C)  Both answers "a" and "b" 
A)  circumstellar disks 
B)  jets 
C)  Both answers "a" and "b"

Question 7

Hydrostatic equilibrium refers to the balance between weight and pressure.

Accepted Answer

A) True 
 B)False

Question 8

T Tauri stars are believed to be young,high mass main sequence stars.

Accepted Answer

A) True 
 B)False

Question 9

Opacity is

Accepted Answer

A)  the balance between the pressure and force of gravity inside a star. 
B)  the force that binds protons and neutrons together to form a nucleus. 
C)  the force that binds an electron to the nucleus in an atom. 
D)  a measure of the ease with which photons can pass through a gas. 
E)  the temperature and density at which a gas will undergo thermonuclear fusion. 
A)  the balance between the pressure and force of gravity inside a star. 
B)  the force that binds protons and neutrons together to form a nucleus. 
C)  the force that binds an electron to the nucleus in an atom. 
D)  a measure of the ease with which photons can pass through a gas. 
E)  the temperature and density at which a gas will undergo thermonuclear fusion.

Question 10

____ occurs when most of the material collapsing to form a protostar has fallen into a disk around the star,and a strong wind from the warm protostar ejects material from its poles.

Accepted Answer

A)  An emission nebula 
B)  Hydrostatic equilibrium 
C)  The proton-proton chain 
D)  The thermonuclear fusion of hydrogen 
E)  A bipolar flow 
A)  An emission nebula 
B)  Hydrostatic equilibrium 
C)  The proton-proton chain 
D)  The thermonuclear fusion of hydrogen 
E)  A bipolar flow

Question 11

The H-R diagram of a young star cluster shows

Accepted Answer

A)  that high mass stars have not yet reached the main sequence yet. 
B)  that low mass stars have not yet reached the main sequence yet. 
C)  mainly giant stars. 
D)  no stars since none have reached the main sequence yet. 
A)  that high mass stars have not yet reached the main sequence yet. 
B)  that low mass stars have not yet reached the main sequence yet. 
C)  mainly giant stars. 
D)  no stars since none have reached the main sequence yet.

Question 12

The H-R diagram of a very young star cluster shows ....

Accepted Answer

A)  only high luminosity main sequence stars 
B)  only low luminosity main sequence stars 
C)  only protostars 
D)  both protostars and high luminosity main sequence stars 
A)  only high luminosity main sequence stars 
B)  only low luminosity main sequence stars 
C)  only protostars 
D)  both protostars and high luminosity main sequence stars

In the proton-proton chain

Nuclear fusion in stars is controlled by the dependence of density on mass.

The region of the sun just below the photosphere

The carbon-nitrogen-oxygen cycle

Energy flows by radiation or convection inside stars but almost never by conduction.

The youngest stars in the Orion Nebula and other star-forming regions also show

Hydrostatic equilibrium refers to the balance between weight and pressure.

T Tauri stars are believed to be young,high mass main sequence stars.

Opacity is

____ occurs when most of the material collapsing to form a protostar has fallen into a disk around the star,and a strong wind from the warm protostar ejects material from its poles.

The H-R diagram of a young star cluster shows

The H-R diagram of a very young star cluster shows ....

Here and Now

A Users Guide to the Sky

Cycles of the Moon

The Origin of Modern Astronomy

Gravity

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Interstellar Medium

Stellar Evolution

The Deaths of Stars

Neutron Stars and Black Holes

The Milky Way Galaxy

Galaxies

Active Galaxies and Supermassive Black Holes

Modern Cosmology

The Origin of the Solar System

Earth: the Standard of Comparative Planetology

The Moon and Mercury: Comparing Airless Worlds

Venus and Mars

Jupiter and Saturn

Uranus,neptune,and the Kuiper Belt

Meteorites,asteroids,and Comets

Astrobiology: Life on Other Worlds

Filters

Exam 11: The Formation and Structure of Stars

In the proton-proton chain

Nuclear fusion in stars is controlled by the dependence of density on mass.

The region of the sun just below the photosphere

The carbon-nitrogen-oxygen cycle

Energy flows by radiation or convection inside stars but almost never by conduction.

The youngest stars in the Orion Nebula and other star-forming regions also show

Hydrostatic equilibrium refers to the balance between weight and pressure.

T Tauri stars are believed to be young,high mass main sequence stars.

Opacity is

____ occurs when most of the material collapsing to form a protostar has fallen into a disk around the star,and a strong wind from the warm protostar ejects material from its poles.

The H-R diagram of a young star cluster shows

The H-R diagram of a very young star cluster shows ....

Here and Now

A Users Guide to the Sky

Cycles of the Moon

The Origin of Modern Astronomy

Gravity

Light and Telescopes

Atoms and Spectra

The Sun

The Family of Stars

The Interstellar Medium

Stellar Evolution

The Deaths of Stars

Neutron Stars and Black Holes

The Milky Way Galaxy

Galaxies

Active Galaxies and Supermassive Black Holes

Modern Cosmology

The Origin of the Solar System

Earth: the Standard of Comparative Planetology

The Moon and Mercury: Comparing Airless Worlds

Venus and Mars

Jupiter and Saturn

Uranus,neptune,and the Kuiper Belt

Meteorites,asteroids,and Comets

Astrobiology: Life on Other Worlds

Filters