Question 1

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

Accepted Answer

A) several hundred thousand years ago. 
B) 8 minutes ago. 
C) several thousand years ago. 
D) several hundred years ago. 
E) 11 years ago. 
A) several hundred thousand years ago. 
B) 8 minutes ago. 
C) several thousand years ago. 
D) several hundred years ago. 
E) 11 years ago.

Question 2

What would happen if the fusion rate in the core increased but the core could not expand?

Accepted Answer

A) The Sun's core would cool and the rate of fusion would decrease. 
B) The Sun's core would reach a new equilibrium, but at a higher temperature. 
C) The Sun's core would heat and the rate of fusion would increase further. 
D) The Sun's core would reach a new equilibrium, but at a cooler temperature. 
A) The Sun's core would cool and the rate of fusion would decrease. 
B) The Sun's core would reach a new equilibrium, but at a higher temperature. 
C) The Sun's core would heat and the rate of fusion would increase further. 
D) The Sun's core would reach a new equilibrium, but at a cooler temperature.

Question 3

Which of the following is the phase of matter in the Sun?

Accepted Answer

A) gas 
B) liquid 
C) solid 
D) plasma 
E) a mixture of all of the above 
A) gas 
B) liquid 
C) solid 
D) plasma 
E) a mixture of all of the above

Question 4

Why are neutrinos so difficult to detect?

Accepted Answer

A) They have no mass. 
B) They are extremely rare. 
C) They have a tendency to pass through just about any material without any interactions. 
D) No one knows; this is the essence of the "solar neutrino problem." 
A) They have no mass. 
B) They are extremely rare. 
C) They have a tendency to pass through just about any material without any interactions. 
D) No one knows; this is the essence of the "solar neutrino problem."

Question 5

How do we know how old the Sun is?

Accepted Answer

A) from Newton's version of Kepler's third law and the orbits of the planets 
B) from ages of solar system meteorites, based on radioactive elements 
C) from calculating its fuel supply and how fast it is using it up 
D) from its speed and distance from us 
A) from Newton's version of Kepler's third law and the orbits of the planets 
B) from ages of solar system meteorites, based on radioactive elements 
C) from calculating its fuel supply and how fast it is using it up 
D) from its speed and distance from us

Question 6

Which is closest to the temperature of the Sun's core?

Accepted Answer

A) 1 million K 
B) 100 million K 
C) 100,000 K 
D) 10 million K 
E) 10,000 K 
A) 1 million K 
B) 100 million K 
C) 100,000 K 
D) 10 million K 
E) 10,000 K

Question 7

Every second, the Sun converts about 600 million tons of hydrogen into 596 million tons of helium. The remaining 4 million tons of mass is .

Accepted Answer

A) reabsorbed as molecular hydrogen 
B) ejected into space by solar flares 
C) converted to an amount of energy equal to 4 million tons times the speed of light squared 
D) ejected into space in a solar wind 
A) reabsorbed as molecular hydrogen 
B) ejected into space by solar flares 
C) converted to an amount of energy equal to 4 million tons times the speed of light squared 
D) ejected into space in a solar wind

Question 8

Energy from the core of the Sun first travels slowly through a convection zone and then much faster through the outer radiation zone.

Accepted Answer

A) True 
 B)False

Question 9

How can we best observe the Sun's chromosphere and corona?

Accepted Answer

A) The chromosphere and corona are both best studied with radio telescopes. 
B) The chromosphere is best observed with ultraviolet telescopes and the corona is best observed with X- ray telescopes. 
C) The chromosphere and corona are both best studied with visible light. 
D) The chromosphere is best observed with infrared telescopes and the corona is best observed with ultraviolet telescopes. 
A) The chromosphere and corona are both best studied with radio telescopes. 
B) The chromosphere is best observed with ultraviolet telescopes and the corona is best observed with X- ray telescopes. 
C) The chromosphere and corona are both best studied with visible light. 
D) The chromosphere is best observed with infrared telescopes and the corona is best observed with ultraviolet telescopes.

Question 10

To estimate the central temperature of the Sun, scientists _.

Accepted Answer

A) monitor changes in Earth's atmosphere 
B) use computer models to predict interior conditions 
C) send probes to measure the temperature 
D) use hot gas to create a small Sun in a laboratory 
A) monitor changes in Earth's atmosphere 
B) use computer models to predict interior conditions 
C) send probes to measure the temperature 
D) use hot gas to create a small Sun in a laboratory

Question 11

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

Question 12

At the time the hypothesis was suggested, what major problem was identified with the idea that the Sun was powered by gravitational contraction?

Accepted Answer

A) This process could not possibly lead to the observed power output of the Sun. 
B) Contracting objects cool down rather than heat up. 
C) 19th century astronomers should have been able to measure the required change in the Sun's size. 
D) This process would power the Sun for only about 25 million years, but geologists already had evidence the Earth was much older than that. 
A) This process could not possibly lead to the observed power output of the Sun. 
B) Contracting objects cool down rather than heat up. 
C) 19th century astronomers should have been able to measure the required change in the Sun's size. 
D) This process would power the Sun for only about 25 million years, but geologists already had evidence the Earth was much older than that.

Question 13

The intricate patterns visible in an X- ray image of the Sun generally show _ .

Accepted Answer

A) structure within sunspots 
B) extremely hot plasma flowing along magnetic field lines 
C) helioseismological fluctuations 
D) a bubbling pattern on the photosphere 
A) structure within sunspots 
B) extremely hot plasma flowing along magnetic field lines 
C) helioseismological fluctuations 
D) a bubbling pattern on the photosphere

Question 14

A computer accessory salesman attempts to convince you to purchase a "solar neutrino" shield for your new computer. (It's even "on sale"!)Why do you turn down this excellent offer?

Accepted Answer

A) Solar neutrinos are generated by solar winds, but we're in a solar minimum now, so the risk of damage is very low. 
B) Neutrinos rarely, if ever, interact with your computer. 
C) There's no such thing as a solar neutrino. 
D) The Earth's natural magnetic field already offers excellent protection against the onslaught of solar neutrinos. 
A) Solar neutrinos are generated by solar winds, but we're in a solar minimum now, so the risk of damage is very low. 
B) Neutrinos rarely, if ever, interact with your computer. 
C) There's no such thing as a solar neutrino. 
D) The Earth's natural magnetic field already offers excellent protection against the onslaught of solar neutrinos.

Question 15

What is shown by the small- scale changes in the shading in the figure above?

Accepted Answer

A) variations in the height of the solar surface 
B) variations in the temperature of the photosphere 
C) vibrations seen at the solar surface 
D) Nothing; this is an artist's rendering of the sun. 
A) variations in the height of the solar surface 
B) variations in the temperature of the photosphere 
C) vibrations seen at the solar surface 
D) Nothing; this is an artist's rendering of the sun.

Question 16

Order the interior layers of the Sun from the hottest to the coldest.

Accepted Answer

A) radiation zone, core, convection zone, photosphere 
B) photosphere, convection zone, core, radiation zone 
C) photosphere, convection zone, radiation zone, core 
D) core, radiation zone, convection zone, photosphere 
A) radiation zone, core, convection zone, photosphere 
B) photosphere, convection zone, core, radiation zone 
C) photosphere, convection zone, radiation zone, core 
D) core, radiation zone, convection zone, photosphere

Question 17

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

Accepted Answer

A) 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. 
B) 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. 
C) 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. 
D) Nuclei have to be very hot in order to fuse, and the only way to get them hot is to bring them close together. 
A) 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. 
B) 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. 
C) 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. 
D) Nuclei have to be very hot in order to fuse, and the only way to get them hot is to bring them close together.

Question 18

Which of the following is not a characteristic of the 11- year sunspot cycle?

Accepted Answer

A) The number of sunspots on the Sun at any one time gradually rises and falls, with an average of 11 years between the times when sunspots are most numerous. 
B) The sunspot cycle is very steady, so that each 11- year cycle is nearly identical to every other 11- year cycle. 
C) The Sun's entire magnetic field flip- flops with each cycle, so that the overall magnetic cycle averages 22 years. 
D) The likelihood of seeing solar prominences or solar flares is higher when sunspots are more common and lower when they are less common. 
A) The number of sunspots on the Sun at any one time gradually rises and falls, with an average of 11 years between the times when sunspots are most numerous. 
B) The sunspot cycle is very steady, so that each 11- year cycle is nearly identical to every other 11- year cycle. 
C) The Sun's entire magnetic field flip- flops with each cycle, so that the overall magnetic cycle averages 22 years. 
D) The likelihood of seeing solar prominences or solar flares is higher when sunspots are more common and lower when they are less common.

Question 19

It takes years for the sun to progress through one sunspot cycle from a maximum area covered with sunspots, to a minimum, and back to a maximum. Refer to the graph above.

Accepted Answer

A) about 1 year 
B) about 110 years 
C) about 10 years 
D) This figure cannot be used to answer this question. 
A) about 1 year 
B) about 110 years 
C) about 10 years 
D) This figure cannot be used to answer this question.

Question 20

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

Accepted Answer

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

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

What would happen if the fusion rate in the core increased but the core could not expand?

Which of the following is the phase of matter in the Sun?

Why are neutrinos so difficult to detect?

How do we know how old the Sun is?

Which is closest to the temperature of the Sun's core?

Every second, the Sun converts about 600 million tons of hydrogen into 596 million tons of helium. The remaining 4 million tons of mass is .

Energy from the core of the Sun first travels slowly through a convection zone and then much faster through the outer radiation zone.

How can we best observe the Sun's chromosphere and corona?

To estimate the central temperature of the Sun, scientists _.

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?

At the time the hypothesis was suggested, what major problem was identified with the idea that the Sun was powered by gravitational contraction?

The intricate patterns visible in an X- ray image of the Sun generally show _ .

A computer accessory salesman attempts to convince you to purchase a "solar neutrino" shield for your new computer. (It's even "on sale"!)Why do you turn down this excellent offer?

What is shown by the small- scale changes in the shading in the figure above?

Order the interior layers of the Sun from the hottest to the coldest.

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

Which of the following is not a characteristic of the 11- year sunspot cycle?

It takes years for the sun to progress through one sunspot cycle from a maximum area covered with sunspots, to a minimum, and back to a maximum. Refer to the graph above.

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

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

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Exam 11: Our Star

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

What would happen if the fusion rate in the core increased but the core could not expand?

Which of the following is the phase of matter in the Sun?

Why are neutrinos so difficult to detect?

How do we know how old the Sun is?

Which is closest to the temperature of the Sun's core?

Every second, the Sun converts about 600 million tons of hydrogen into 596 million tons of helium. The remaining 4 million tons of mass is .

Energy from the core of the Sun first travels slowly through a convection zone and then much faster through the outer radiation zone.

How can we best observe the Sun's chromosphere and corona?

To estimate the central temperature of the Sun, scientists _.

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?

At the time the hypothesis was suggested, what major problem was identified with the idea that the Sun was powered by gravitational contraction?

The intricate patterns visible in an X- ray image of the Sun generally show _ .

A computer accessory salesman attempts to convince you to purchase a "solar neutrino" shield for your new computer. (It's even "on sale"!)Why do you turn down this excellent offer?

What is shown by the small- scale changes in the shading in the figure above?

Order the interior layers of the Sun from the hottest to the coldest.

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

Which of the following is not a characteristic of the 11- year sunspot cycle?

It takes years for the sun to progress through one sunspot cycle from a maximum area covered with sunspots, to a minimum, and back to a maximum. Refer to the graph above.

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

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