Question 1

High mass stars evolve more slowly to the main sequence than lower mass stars.

Accepted Answer

A) True 
 B)False  False

Question 2

A star on the ____________________ generates enough energy from nuclear fusion to halt gravitational collapse.

Accepted Answer

main-sequence

Question 3

The condition of ____________________ means that the force due to gravity pushing down on a layer is exactly equal to the pressure pushing outward on that layer.

Accepted Answer

hydrostatic equilibrium

Question 4

The factors that resist collapse in a gas cloud are

Accepted Answer

A)  I,III,& V 
B)  I,IV,& V 
C)  II,III,& IV 
D)  II,IV,& V 
E)  III,IV,& V 
A)  I,III,& V 
B)  I,IV,& V 
C)  II,III,& IV 
D)  II,IV,& V 
E)  III,IV,& V

Question 5

If the sun produces energy by the proton-proton chain,then the center of the sun must have a temperature of at least

Accepted Answer

A)  104 K 
B)  107 K 
C)  1010 K 
D)  1013 K 
E)  1016 K 
A)  104 K 
B)  107 K 
C)  1010 K 
D)  1013 K 
E)  1016 K

Question 6

What force(s)are responsible for the collapse of an interstellar cloud?

Accepted Answer

A)  nuclear 
B)  gravity 
C)  electric 
D)  magnetic 
E)  Both c and d 
A)  nuclear 
B)  gravity 
C)  electric 
D)  magnetic 
E)  Both c and d

Question 7

Ninety percent of all stars fuse helium and lie on the main sequence.

Accepted Answer

A) True 
 B)False

Question 8

Stars with masses greater than 1.1 solar masses use the ____________________ to convert H into He and energy.

Accepted Answer

The answer of Stars with masses greater than 1.1 solar...

Question 9

The diagram below is an HR diagram.The line indicates the location of the main sequence.Which of the five labeled locations on the HR diagram indicates a luminosity and temperature similar to that of a T Tauri star?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  5 
A)  1 
B)  2 
C)  3 
D)  4 
E)  5

Question 10

The sun makes most of its energy by the CNO cycle.

Accepted Answer

A) True 
 B)False

Question 11

Ionization from the ____ in the Orion Nebula makes it glow.

Accepted Answer

A)  planets 
B)  coolest star 
C)  hottest star 
A)  planets 
B)  coolest star 
C)  hottest star

Question 12

Energy transport by ____________________ is important when photons cannot readily travel through a gas.

Accepted Answer

The answer of Energy transport by ____________________ is important when...

Question 13

____________________ is the resistance of a gas to the flow of radiation.

Accepted Answer

The answer of ____________________ is the resistance of a gas...

Question 14

Ionization from the ____ in the Orion Nebula makes it glow.

Accepted Answer

A)  planets 
B)  coolest star 
C)  hottest star 
A)  planets 
B)  coolest star 
C)  hottest star

Question 15

The proton-proton chain needs high temperature because

Accepted Answer

A)  of the ground state energy of the hydrogen atom. 
B)  of the presence of helium atoms. 
C)  the protons must overcome the Coulomb barrier. 
D)  of the need for low density. 
E)  the neutrinos carry more energy away than the reaction produces. 
A)  of the ground state energy of the hydrogen atom. 
B)  of the presence of helium atoms. 
C)  the protons must overcome the Coulomb barrier. 
D)  of the need for low density. 
E)  the neutrinos carry more energy away than the reaction produces.

Question 16

As a star begin to form the initial energy source is from

Accepted Answer

A)  nuclear fusion. 
B)  nuclear fission. 
C)  gravitational potential energy. 
D)  magnetic fields. 
A)  nuclear fusion. 
B)  nuclear fission. 
C)  gravitational potential energy. 
D)  magnetic fields.

Question 17

Interstellar gas clouds may collapse to form stars if they

Accepted Answer

A)  have very high temperatures. 
B)  encounter a shock wave. 
C)  rotate rapidly. 
D)  are located near main sequence spectral type K and M stars. 
E)  all of the above 
A)  have very high temperatures. 
B)  encounter a shock wave. 
C)  rotate rapidly. 
D)  are located near main sequence spectral type K and M stars. 
E)  all of the above

Question 18

____ is the thermonuclear fusion of hydrogen to form helium operating in the cores of massive stars on the main sequence.

Accepted Answer

A)  The CNO cycle 
B)  The proton-proton chain 
C)  Hydrostatic equilibrium 
D)  The neutrino process 
E)  none of the above 
A)  The CNO cycle 
B)  The proton-proton chain 
C)  Hydrostatic equilibrium 
D)  The neutrino process 
E)  none of the above

Question 19

What causes the outward pressure that balances the inward pull of gravity in a star?

Accepted Answer

A)  the outward flow of energy 
B)  the opacity of the gas 
C)  the temperature of the gas 
D)  the density of the gas 
E)  c and d 
A)  the outward flow of energy 
B)  the opacity of the gas 
C)  the temperature of the gas 
D)  the density of the gas 
E)  c and d

Question 20

The nuclear reactions in a star's core remain under control so long as

Accepted Answer

A)  luminosity depends on mass. 
B)  pressure depends on temperature. 
C)  density depends on mass. 
D)  weight depends on temperature. 
E)  temperature depends on mass. 
A)  luminosity depends on mass. 
B)  pressure depends on temperature. 
C)  density depends on mass. 
D)  weight depends on temperature. 
E)  temperature depends on mass.

Exam 11: The Formation and Structure of Stars

High mass stars evolve more slowly to the main sequence than lower mass stars.

A star on the ____________________ generates enough energy from nuclear fusion to halt gravitational collapse.

The condition of ____________________ means that the force due to gravity pushing down on a layer is exactly equal to the pressure pushing outward on that layer.

The factors that resist collapse in a gas cloud are

If the sun produces energy by the proton-proton chain,then the center of the sun must have a temperature of at least

What force(s)are responsible for the collapse of an interstellar cloud?

Ninety percent of all stars fuse helium and lie on the main sequence.

Stars with masses greater than 1.1 solar masses use the ____________________ to convert H into He and energy.

The diagram below is an HR diagram.The line indicates the location of the main sequence.Which of the five labeled locations on the HR diagram indicates a luminosity and temperature similar to that of a T Tauri star?

The sun makes most of its energy by the CNO cycle.

Ionization from the ____ in the Orion Nebula makes it glow.

Energy transport by ____________________ is important when photons cannot readily travel through a gas.

____________________ is the resistance of a gas to the flow of radiation.

Ionization from the ____ in the Orion Nebula makes it glow.

The proton-proton chain needs high temperature because

As a star begin to form the initial energy source is from

Interstellar gas clouds may collapse to form stars if they

____ is the thermonuclear fusion of hydrogen to form helium operating in the cores of massive stars on the main sequence.

What causes the outward pressure that balances the inward pull of gravity in a star?

The nuclear reactions in a star's core remain under control so long as

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

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