Question 1

The Sun's surface, as we see it with our eyes, is called the ________.

Accepted Answer

A)  photosphere 
B)  chromosphere 
C)  corona 
D)  core 
A)  photosphere 
B)  chromosphere 
C)  corona 
D)  core

Question 2

The Sun's surface seethes and churns with a bubbling pattern. Why?

Accepted Answer

A)  We are seeing hot gas rising and cool gas falling due to the convection that occurs beneath the surface. 
B)  The Sun's surface is boiling. 
C)  The churning gas is being stirred up by the strong solar wind. 
D)  The churning is an illusion created by varying radiation, as the gas on the Sun's surface is actually quite still. 
A)  We are seeing hot gas rising and cool gas falling due to the convection that occurs beneath the surface. 
B)  The Sun's surface is boiling. 
C)  The churning gas is being stirred up by the strong solar wind. 
D)  The churning is an illusion created by varying radiation, as the gas on the Sun's surface is actually quite still.

Question 3

What is the only force that can overcome the repulsion between two positively charged nuclei to bind them into an atomic nucleus?

Accepted Answer

A)  The strong force 
B)  The weak force 
C)  The electromagnetic force 
D)  The gravitational force 
E)  The Coriolis force 
A)  The strong force 
B)  The weak force 
C)  The electromagnetic force 
D)  The gravitational force 
E)  The Coriolis force

Question 4

Nuclear Fusion Power Plants: The public often reacts with fear to any energy source involving the word "nuclear." Imagine that you are discussion the problem of energy generation with a friend, and you mention that nuclear fusion power plants should be investigated. Your friend expresses worry about all of the nuclear waste that would be produced. How would you explain to your friend that this fear is misplaced?

Accepted Answer

I would explain to my friend that nuclea

Question 5

The Sun generates energy primarily by nuclear fission.

Accepted Answer

A) True 
 B)False

Question 6

What would happen in the Sun if the temperature of the core decreased?

Accepted Answer

A)  The fusion rate decreases, then the core shrinks and heats. 
B)  The fusion rate decreases, then the core expands and heats. 
C)  The fusion rate increases, then the core expands and cools. 
D)  The fusion rate increases, then the core shrinks and heats. 
A)  The fusion rate decreases, then the core shrinks and heats. 
B)  The fusion rate decreases, then the core expands and heats. 
C)  The fusion rate increases, then the core expands and cools. 
D)  The fusion rate increases, then the core shrinks and heats.

Question 7

How much mass does the Sun lose through nuclear fusion per second?

Accepted Answer

A)  4 tons 
B)  4 million tons 
C)  600 tons 
D)  600 million tons 
E)  Nothing: mass-energy is conserved. 
A)  4 tons 
B)  4 million tons 
C)  600 tons 
D)  600 million tons 
E)  Nothing: mass-energy is conserved.

Question 8

What was the solar neutrino problem?

Accepted Answer

Electron neutrinos coming from the Sun h

Question 9

Suppose you try to bring two protons close together. Because of the electromagnetic force, the two protons will

Accepted Answer

A)  collide. 
B)  remain stationary. 
C)  attract one another. 
D)  repel one another. 
E)  join together to form a deuterium nucleus. 
A)  collide. 
B)  remain stationary. 
C)  attract one another. 
D)  repel one another. 
E)  join together to form a deuterium nucleus.

Question 10

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

Question 11

Why does the Sun emit neutrinos?

Accepted Answer

A)  Solar flares create neutrinos with magnetic fields. 
B)  Fusion in the Sun's core creates neutrinos. 
C)  Convection releases neutrinos, which random walk through the radiation zone. 
D)  The Sun was born with a supply of neutrinos that it gradually emits into space. 
E)  The Sun does not emit neutrinos. 
A)  Solar flares create neutrinos with magnetic fields. 
B)  Fusion in the Sun's core creates neutrinos. 
C)  Convection releases neutrinos, which random walk through the radiation zone. 
D)  The Sun was born with a supply of neutrinos that it gradually emits into space. 
E)  The Sun does not emit neutrinos.

Question 12

The star Alpha Centauri A is the same type of star as the Sun, but its luminosity is about 1.6 times that of the Sun. What can we conclude?

Accepted Answer

A)  Alpha Centauri A fuses hydrogen into helium in its core at a higher rate than our Sun. 
B)  Alpha Centauri A has a much higher surface temperature than the Sun. 
C)  Alpha Centauri A is much farther from Earth than the Sun. 
D)  Alpha Centauri A must have a vastly different interior structure than the Sun. 
A)  Alpha Centauri A fuses hydrogen into helium in its core at a higher rate than our Sun. 
B)  Alpha Centauri A has a much higher surface temperature than the Sun. 
C)  Alpha Centauri A is much farther from Earth than the Sun. 
D)  Alpha Centauri A must have a vastly different interior structure than the Sun.

Question 13

What are coronal holes?

Accepted Answer

A)  regions in the photosphere where magnetic lines gather, creating cooler areas with much less plasma 
B)  areas of the corona where magnetic field lines project out into space, allowing charged particles to escape and form the solar wind 
C)  areas in the corona that allow us to see through to the photosphere 
D)  tunnels in the outer layers of the Sun that allow photons to escape and form the solar wind 
E)  all of the above 
A)  regions in the photosphere where magnetic lines gather, creating cooler areas with much less plasma 
B)  areas of the corona where magnetic field lines project out into space, allowing charged particles to escape and form the solar wind 
C)  areas in the corona that allow us to see through to the photosphere 
D)  tunnels in the outer layers of the Sun that allow photons to escape and form the solar wind 
E)  all of the above

Question 14

If the Sun's core suddenly shrank a little bit, what would happen in the Sun?

Accepted Answer

A)  The core would heat up, fusion rates would increase, the core would re-expand. 
B)  The core would cool off and continue to shrink as its density increased. 
C)  The density of the core would decrease, causing the core to cool off and expand. 
D)  The core would heat up, causing it to radiate so much energy that it would shrink even more. 
A)  The core would heat up, fusion rates would increase, the core would re-expand. 
B)  The core would cool off and continue to shrink as its density increased. 
C)  The density of the core would decrease, causing the core to cool off and expand. 
D)  The core would heat up, causing it to radiate so much energy that it would shrink even more.

Question 15

Where in the Sun do fusion reactions happen?

Accepted Answer

A)  Core and radiation zone 
B)  Everywhere inside the Sun 
C)  Only the core 
A)  Core and radiation zone 
B)  Everywhere inside the Sun 
C)  Only the core

Question 16

Which of the following best explains why nuclear fusion requires bringing nuclei extremely close together?

Accepted Answer

A)  Nuclei normally repel because they are all positively charged and can be made to stick only when brought close enough for the strong force to take hold. 
B)  Nuclei are attracted to each other by the electromagnetic force, but this force is only strong enough to make nuclei stick when they are very close together. 
C)  Nuclei have to be very hot in order to fuse, and the only way to get them hot is to bring them close together. 
D)  Fusion can proceed only by the proton-proton chain, and therefore requires that protons come close enough together to be linked up into a chain. 
A)  Nuclei normally repel because they are all positively charged and can be made to stick only when brought close enough for the strong force to take hold. 
B)  Nuclei are attracted to each other by the electromagnetic force, but this force is only strong enough to make nuclei stick when they are very close together. 
C)  Nuclei have to be very hot in order to fuse, and the only way to get them hot is to bring them close together. 
D)  Fusion can proceed only by the proton-proton chain, and therefore requires that protons come close enough together to be linked up into a chain.

Question 17

Although the Sun does not generate energy by gravitational contraction today, this energy-generation mechanism was important when the Sun was forming.

Accepted Answer

A) True 
 B)False

Question 18

What is the solution to the solar neutrino problem?

Accepted Answer

A)  The Sun is generating energy other than by nuclear fusion. 
B)  The Sun is generating much less energy than we think it is. 
C)  We did not know how to detect neutrinos. 
D)  Not all fusion reactions create neutrinos. 
E)  The electron neutrinos created in the Sun's core change into another type of neutrino that we did not detect. 
A)  The Sun is generating energy other than by nuclear fusion. 
B)  The Sun is generating much less energy than we think it is. 
C)  We did not know how to detect neutrinos. 
D)  Not all fusion reactions create neutrinos. 
E)  The electron neutrinos created in the Sun's core change into another type of neutrino that we did not detect.

Question 19

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

Accepted Answer

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

Question 20

Which of the following statements about the Sun is an inference from a model, not an observation?

Accepted Answer

A)  The Sun emits neutrinos. 
B)  The convection zone is cooler than the radiation zone. 
C)  The photosphere emits visible light. 
D)  The corona is hotter than the photosphere. 
A)  The Sun emits neutrinos. 
B)  The convection zone is cooler than the radiation zone. 
C)  The photosphere emits visible light. 
D)  The corona is hotter than the photosphere.

The Sun's surface, as we see it with our eyes, is called the ________.

The Sun's surface seethes and churns with a bubbling pattern. Why?

What is the only force that can overcome the repulsion between two positively charged nuclei to bind them into an atomic nucleus?

The Sun generates energy primarily by nuclear fission.

What would happen in the Sun if the temperature of the core decreased?

How much mass does the Sun lose through nuclear fusion per second?

What was the solar neutrino problem?

Suppose you try to bring two protons close together. Because of the electromagnetic force, the two protons will

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

Why does the Sun emit neutrinos?

The star Alpha Centauri A is the same type of star as the Sun, but its luminosity is about 1.6 times that of the Sun. What can we conclude?

What are coronal holes?

If the Sun's core suddenly shrank a little bit, what would happen in the Sun?

Where in the Sun do fusion reactions happen?

Which of the following best explains why nuclear fusion requires bringing nuclei extremely close together?

Although the Sun does not generate energy by gravitational contraction today, this energy-generation mechanism was important when the Sun was forming.

What is the solution to the solar neutrino problem?

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

Which of the following statements about the Sun is an inference from a model, not an observation?

Our Place in 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 Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

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

Surveying the Stars

Star Stuff

Bizarre Stellar Graveyard

Our Galaxy

Galaxies and the Foundation of Modern Cosmology

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

The Beginning of Time

Life in the Universe

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Exam 10: Our Star

The Sun's surface, as we see it with our eyes, is called the ________.

The Sun's surface seethes and churns with a bubbling pattern. Why?

What is the only force that can overcome the repulsion between two positively charged nuclei to bind them into an atomic nucleus?

The Sun generates energy primarily by nuclear fission.

What would happen in the Sun if the temperature of the core decreased?

How much mass does the Sun lose through nuclear fusion per second?

What was the solar neutrino problem?

Suppose you try to bring two protons close together. Because of the electromagnetic force, the two protons will

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

Why does the Sun emit neutrinos?

The star Alpha Centauri A is the same type of star as the Sun, but its luminosity is about 1.6 times that of the Sun. What can we conclude?

What are coronal holes?

If the Sun's core suddenly shrank a little bit, what would happen in the Sun?

Where in the Sun do fusion reactions happen?

Which of the following best explains why nuclear fusion requires bringing nuclei extremely close together?

Although the Sun does not generate energy by gravitational contraction today, this energy-generation mechanism was important when the Sun was forming.

What is the solution to the solar neutrino problem?

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

Which of the following statements about the Sun is an inference from a model, not an observation?

Our Place in 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 Planetary Systems: Our Solar System and Beyond

Earth and the Terrestrial Worlds

Jovian Planet Systems

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

Surveying the Stars

Star Stuff

Bizarre Stellar Graveyard

Our Galaxy

Galaxies and the Foundation of Modern Cosmology

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

The Beginning of Time

Life in the Universe

Filters