Question 1

What do we mean when we say that the Sun is in gravitational equilibrium?

Accepted Answer

A) The Sun maintains a steady temperature. 
B) There is a balance within the Sun between the outward push of pressure and the inward pull of gravity. 
C) The hydrogen gas in the Sun is balanced so that it never rises upward or falls downward. 
D) The Sun always has the same amount of mass, creating the same gravitational force. 
A) The Sun maintains a steady temperature. 
B) There is a balance within the Sun between the outward push of pressure and the inward pull of gravity. 
C) The hydrogen gas in the Sun is balanced so that it never rises upward or falls downward. 
D) The Sun always has the same amount of mass, creating the same gravitational force.

Question 2

By what process does the Sun generate energy?

Accepted Answer

A) nuclear fission 
B) nuclear fusion 
C) chemical reactions 
D) gradual expansion 
E) gravitational contraction 
A) nuclear fission 
B) nuclear fusion 
C) chemical reactions 
D) gradual expansion 
E) gravitational contraction

Question 3

The light radiated from the Sun's surface reaches Earth in about 8 minutes, but the energy of that light was released by fusion in the solar core about .

Accepted Answer

A) a few hundred thousand years ago 
B) three days ago 
C) one thousand years ago 
D) one hundred years ago 
A) a few hundred thousand years ago 
B) three days ago 
C) one thousand years ago 
D) one hundred years ago

Question 4

The overall result of the proton- proton chain is .

Accepted Answer

A) 6 H becomes 1 He + energy 
B) 4 H becomes 1 He + energy 
C) p + p becomes 2H + energy 
D) individual protons are joined into long chains of protons 
A) 6 H becomes 1 He + energy 
B) 4 H becomes 1 He + energy 
C) p + p becomes 2H + energy 
D) individual protons are joined into long chains of protons

Question 5

Nuclear power plants on Earth create energy in the same way as the Sun.

Accepted Answer

A) True 
 B)False

Question 6

Studying the chromosphere and corona: Consider observations of the solar chromosphere and corona. What are the principle difficulties in observing them in X- ray, ultraviolet, and in visible light? What could be done to circumvent those difficulties?

Accepted Answer

X- ray light and ultraviolet light do no

Question 7

What is the solar thermostat?

Accepted Answer

The solar thermostat is a natural feedba

Question 8

The proton- proton chain is _ .

Accepted Answer

A) another name for the force that holds protons together in atomic nuclei 
B) the specific set of nuclear reactions through which the Sun fuses hydrogen into helium 
C) an alternative way of generating energy that is different from the fusion of hydrogen into helium 
D) the linkage of numerous protons into long chains 
A) another name for the force that holds protons together in atomic nuclei 
B) the specific set of nuclear reactions through which the Sun fuses hydrogen into helium 
C) an alternative way of generating energy that is different from the fusion of hydrogen into helium 
D) the linkage of numerous protons into long chains

Question 9

Which of the following correctly compares the Sun's energy generation process to the energy generation process in human- built nuclear power plants?

Accepted Answer

A) The Sun generates energy by fusing small nuclei into larger ones, while our power plants generate energy by the fission (splitting)of large nuclei. 
B) Both processes involve nuclear fusion, but the Sun fuses hydrogen while nuclear power plants fuse uranium. 
C) The Sun generates energy through fission while nuclear power plants generate energy through fusion. 
D) The Sun generates energy through nuclear reactions while nuclear power plants generate energy through chemical reactions. 
A) The Sun generates energy by fusing small nuclei into larger ones, while our power plants generate energy by the fission (splitting)of large nuclei. 
B) Both processes involve nuclear fusion, but the Sun fuses hydrogen while nuclear power plants fuse uranium. 
C) The Sun generates energy through fission while nuclear power plants generate energy through fusion. 
D) The Sun generates energy through nuclear reactions while nuclear power plants generate energy through chemical reactions.

Question 10

Which has a greater mass?

Accepted Answer

A) two neutrons and two protons in a helium nucleus 
B) four protons 
C) A and B both have exactly the same mass. 
A) two neutrons and two protons in a helium nucleus 
B) four protons 
C) A and B both have exactly the same mass.

Question 11

How does the Sun's mass compare to Earth's mass?

Accepted Answer

A) The Sun's mass is about 30 times the mass of the Earth. 
B) The Sun's mass is about 300,000 times the mass of the Earth. 
C) The Sun's mass is about 300 times the mass of the Earth. 
D) Both have approximately the same mass. 
A) The Sun's mass is about 30 times the mass of the Earth. 
B) The Sun's mass is about 300,000 times the mass of the Earth. 
C) The Sun's mass is about 300 times the mass of the Earth. 
D) Both have approximately the same mass.

Question 12

Sunspots are cooler than the surrounding region of the Sun's surface.

Accepted Answer

A) True 
 B)False

Question 13

What keeps the Sun's outer layers from continuing to fall inward in a gravitational collapse?

Accepted Answer

A) outward pressure due to super- heated gas 
B) electromagnetic repulsion between protons 
C) the strong force between protons 
D) neutrinos produced by nuclear fusion drag gas outward 
A) outward pressure due to super- heated gas 
B) electromagnetic repulsion between protons 
C) the strong force between protons 
D) neutrinos produced by nuclear fusion drag gas outward

Question 14

The Sun will exhaust its nuclear fuel in about .

Accepted Answer

A) 5 billion years 
B) 5 million years 
C) 50 billion years 
D) 5000 AD 
A) 5 billion years 
B) 5 million years 
C) 50 billion years 
D) 5000 AD

Question 15

If the Sun suddenly stopped emitting neutrinos, what might we infer (after checking that our neutrino detectors were still operational)?

Accepted Answer

A) Fusion reactions in the Sun ceased a few hundred thousand years ago. 
B) The Sun has exhausted its supply of neutrinos. 
C) Fission reactions in the Sun have ceased. 
D) Fusion reactions in the Sun have ceased. 
A) Fusion reactions in the Sun ceased a few hundred thousand years ago. 
B) The Sun has exhausted its supply of neutrinos. 
C) Fission reactions in the Sun have ceased. 
D) Fusion reactions in the Sun have ceased.

Question 16

How can we measure the strength of magnetic fields on the Sun?

Accepted Answer

A) by observing auroras here on Earth 
B) by looking for the splitting of spectral lines in the Sun's spectrum 
C) by observing the sizes of sunspots: Bigger sunspots mean a stronger field 
D) only by using sophisticated computer models because there are no observational ways of measuring magnetic field strength 
A) by observing auroras here on Earth 
B) by looking for the splitting of spectral lines in the Sun's spectrum 
C) by observing the sizes of sunspots: Bigger sunspots mean a stronger field 
D) only by using sophisticated computer models because there are no observational ways of measuring magnetic field strength

Question 17

Which of the following best describes why the Sun emits most of its energy in the form of visible light?

Accepted Answer

A) Nuclear fusion in the Sun's core produces visible light photons. 
B) The Sun's gas is on fire like flames from wood or coal, and these flames emit visible light. 
C) Like all objects, the Sun emits thermal radiation with a spectrum that depends on its temperature, and the Sun's surface temperature is just right for emitting mostly visible light. 
D) The visible light comes from energy level transitions as electrons in the Sun's hydrogen atoms jump between level 1 and level 2. 
A) Nuclear fusion in the Sun's core produces visible light photons. 
B) The Sun's gas is on fire like flames from wood or coal, and these flames emit visible light. 
C) Like all objects, the Sun emits thermal radiation with a spectrum that depends on its temperature, and the Sun's surface temperature is just right for emitting mostly visible light. 
D) The visible light comes from energy level transitions as electrons in the Sun's hydrogen atoms jump between level 1 and level 2.

Question 18

How is the sunspot cycle directly relevant to us here on Earth?

Accepted Answer

A) The brightening and darkening of the Sun that occurs during the sunspot cycle affects plant photosynthesis here on Earth. 
B) The Sun's magnetic field, which plays a major role in the sunspot cycle, affects compass needles that we use on Earth. 
C) The sunspot cycle is the cause of global warming. 
D) Coronal mass ejections and other activity associated with the sunspot cycle can disrupt radio communications and knock out sensitive electronic equipment. 
E) The sunspot cycle strongly influences Earth's weather. 
A) The brightening and darkening of the Sun that occurs during the sunspot cycle affects plant photosynthesis here on Earth. 
B) The Sun's magnetic field, which plays a major role in the sunspot cycle, affects compass needles that we use on Earth. 
C) The sunspot cycle is the cause of global warming. 
D) Coronal mass ejections and other activity associated with the sunspot cycle can disrupt radio communications and knock out sensitive electronic equipment. 
E) The sunspot cycle strongly influences Earth's weather.

Question 19

Describe some of the early theories for the Sun's energy source and why they are no longer accepted as viable.

Accepted Answer

One early idea was that the Sun shone th

Question 20

What happens to energy in the Sun's convection zone?

Accepted Answer

A) Energy is produced in the convection zone by thermal radiation. 
B) Energy is produced in the convection zone by nuclear fusion. 
C) Energy is transported outward by the rising of hot plasma. 
D) Energy slowly leaks outward through the radiative diffusion of photons that repeatedly bounce off ions and electrons. 
A) Energy is produced in the convection zone by thermal radiation. 
B) Energy is produced in the convection zone by nuclear fusion. 
C) Energy is transported outward by the rising of hot plasma. 
D) Energy slowly leaks outward through the radiative diffusion of photons that repeatedly bounce off ions and electrons.

What do we mean when we say that the Sun is in gravitational equilibrium?

By what process does the Sun generate energy?

The light radiated from the Sun's surface reaches Earth in about 8 minutes, but the energy of that light was released by fusion in the solar core about .

The overall result of the proton- proton chain is .

Nuclear power plants on Earth create energy in the same way as the Sun.

Studying the chromosphere and corona: Consider observations of the solar chromosphere and corona. What are the principle difficulties in observing them in X- ray, ultraviolet, and in visible light? What could be done to circumvent those difficulties?

What is the solar thermostat?

The proton- proton chain is _ .

Which of the following correctly compares the Sun's energy generation process to the energy generation process in human- built nuclear power plants?

Which has a greater mass?

How does the Sun's mass compare to Earth's mass?

Sunspots are cooler than the surrounding region of the Sun's surface.

What keeps the Sun's outer layers from continuing to fall inward in a gravitational collapse?

The Sun will exhaust its nuclear fuel in about .

If the Sun suddenly stopped emitting neutrinos, what might we infer (after checking that our neutrino detectors were still operational)?

How can we measure the strength of magnetic fields on the Sun?

Which of the following best describes why the Sun emits most of its energy in the form of visible light?

How is the sunspot cycle directly relevant to us here on Earth?

Describe some of the early theories for the Sun's energy source and why they are no longer accepted as viable.

What happens to energy in the Sun's convection zone?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters

Exam 11: Our Star

What do we mean when we say that the Sun is in gravitational equilibrium?

By what process does the Sun generate energy?

The light radiated from the Sun's surface reaches Earth in about 8 minutes, but the energy of that light was released by fusion in the solar core about .

The overall result of the proton- proton chain is .

Nuclear power plants on Earth create energy in the same way as the Sun.

Studying the chromosphere and corona: Consider observations of the solar chromosphere and corona. What are the principle difficulties in observing them in X- ray, ultraviolet, and in visible light? What could be done to circumvent those difficulties?

What is the solar thermostat?

The proton- proton chain is _ .

Which of the following correctly compares the Sun's energy generation process to the energy generation process in human- built nuclear power plants?

Which has a greater mass?

How does the Sun's mass compare to Earth's mass?

Sunspots are cooler than the surrounding region of the Sun's surface.

What keeps the Sun's outer layers from continuing to fall inward in a gravitational collapse?

The Sun will exhaust its nuclear fuel in about .

If the Sun suddenly stopped emitting neutrinos, what might we infer (after checking that our neutrino detectors were still operational)?

How can we measure the strength of magnetic fields on the Sun?

Which of the following best describes why the Sun emits most of its energy in the form of visible light?

How is the sunspot cycle directly relevant to us here on Earth?

Describe some of the early theories for the Sun's energy source and why they are no longer accepted as viable.

What happens to energy in the Sun's convection zone?

A Modern View of the Universe

Discovering the Universe for Yourself

The Science of Astronomy

Making Sense of the Universe: Understanding Motion, Energy, and Gravity

Light: the Cosmic Messenger

Formation of the Solar System

Earth and the Terrestrial Worlds

Jovian Planet System

Asteroids, Comets, and Dwarf Planets: Their Nature, Orbits, and Impacts

Other Planetary Systems: the New Science of Distant Worlds

Surveying the Stars

Star Stuff

The Bizarre Stellar Graveyard

Our Galaxy

A Universe of Galaxies

The Birth of the Universe

Dark Matter, Dark Energy, and the Fate of the Universe

Life in the Universe

Filters