Question 1

Why does fusion take place at very high temperatures?

Accepted Answer

A)  Gamma rays, a product of fusion reactions, can only exist at very high temperatures. 
B)  High temperatures and pressures are required to confine the hydrogen plasma so that fusion can take place. 
C)  High temperatures mean high collisional velocities, which can allow protons to overcome their mutual electrical repulsion. 
D)  High temperatures produce bluer, more energetic photons that are required to initiate the fusion reaction sequence. 
A)  Gamma rays, a product of fusion reactions, can only exist at very high temperatures. 
B)  High temperatures and pressures are required to confine the hydrogen plasma so that fusion can take place. 
C)  High temperatures mean high collisional velocities, which can allow protons to overcome their mutual electrical repulsion. 
D)  High temperatures produce bluer, more energetic photons that are required to initiate the fusion reaction sequence. C

Question 2

Where does fusion occur in the Sun?

Accepted Answer

A)  the corona 
B)  the photosphere 
C)  the radiative zone 
D)  the core 
A)  the corona 
B)  the photosphere 
C)  the radiative zone 
D)  the core D

Question 3

What is the fate of positrons produced through fusion in the Sun's core?

Accepted Answer

A)  They escape without interacting with matter in the Sun. 
B)  They are annihilated. 
C)  They are carried to the surface through convection. 
D)  They are fused into larger nuclei. 
A)  They escape without interacting with matter in the Sun. 
B)  They are annihilated. 
C)  They are carried to the surface through convection. 
D)  They are fused into larger nuclei. B

Question 4

How are oscillations of the Sun's surface measured?

Accepted Answer

A)  the sunspot cycle 
B)  redshifts and blueshifts of absorption lines 
C)  variations in the solar luminosity 
D)  solar neutrinos 
A)  the sunspot cycle 
B)  redshifts and blueshifts of absorption lines 
C)  variations in the solar luminosity 
D)  solar neutrinos

Question 5

The Sun produces 4 × 10²⁶ joules per second through fusion of hydrogen.How does its mass decrease each second through this process?

Accepted Answer

A)  4 × 106 kg/second 
B)  4 × 107 kg/second 
C)  4 × 108 kg/second 
D)  4 × 109 kg/second 
A)  4 × 106 kg/second 
B)  4 × 107 kg/second 
C)  4 × 108 kg/second 
D)  4 × 109 kg/second

Question 6

Which of the following mechanisms is a result of each and every star in the Universe?

Accepted Answer

A)  nuclear fission 
B)  the formation of brown dwarfs 
C)  supernova explosions 
D)  chemical enrichment by heavy elements 
A)  nuclear fission 
B)  the formation of brown dwarfs 
C)  supernova explosions 
D)  chemical enrichment by heavy elements

Question 7

What type of solar activity is shown in the image below?

Accepted Answer

A)  solar flare 
B)  solar prominence 
C)  coronal mass ejection 
D)  coronal hole 
A)  solar flare 
B)  solar prominence 
C)  coronal mass ejection 
D)  coronal hole

Question 8

Which of the following is a result of the solar dynamo?

Accepted Answer

A)  Flux tubes above the radiative zone become buoyant and rise. 
B)  the differential rotation of the sun. 
C)  solar granulation 
D)  none of the above 
A)  Flux tubes above the radiative zone become buoyant and rise. 
B)  the differential rotation of the sun. 
C)  solar granulation 
D)  none of the above

Question 9

What happens to a gamma ray photon produced in the Sun's interior as it travels through the radiative zone?

Accepted Answer

A)  It breaks apart heavy nuclei, producing more energy. 
B)  It is trapped within a blob of gas and carried upward slowly. 
C)  It streams to the edge of the zone without interacting. 
D)  It scatters every few centimeters and is transformed into many lower energy photons. 
A)  It breaks apart heavy nuclei, producing more energy. 
B)  It is trapped within a blob of gas and carried upward slowly. 
C)  It streams to the edge of the zone without interacting. 
D)  It scatters every few centimeters and is transformed into many lower energy photons.

Question 10

Which of the following lists arranges its constituent nuclei in order from most tightly bound to least tightly bound?

Accepted Answer

A)  helium, deuterium, oxygen, iron 
B)  deuterium, helium, iron, oxygen 
C)  iron, helium, deuterium, oxygen 
D)  iron, oxygen, helium, deuterium 
A)  helium, deuterium, oxygen, iron 
B)  deuterium, helium, iron, oxygen 
C)  iron, helium, deuterium, oxygen 
D)  iron, oxygen, helium, deuterium

Question 11

Before 2002,why did astronomers detect only a fraction of the neutrinos they expected from the Sun?

Accepted Answer

The neutrinos oscillate to oth

Question 12

Arrange the following layers of the Sun in order from most to least dense.

Accepted Answer

A)  radiative zone, core, photosphere, convective zone 
B)  core, convective zone, radiative zone, photosphere 
C)  core, radiative zone, convective zone, photosphere 
D)  radiative zone, convective zone, core, photosphere 
A)  radiative zone, core, photosphere, convective zone 
B)  core, convective zone, radiative zone, photosphere 
C)  core, radiative zone, convective zone, photosphere 
D)  radiative zone, convective zone, core, photosphere

Question 13

The figure below shows the trajectories of particles produced within the Sun.Which kind of particle follows the trajectory labeled "X"?

Accepted Answer

A)  gamma rays 
B)  positrons 
C)  neutrinos 
D)  neutrons 
A)  gamma rays 
B)  positrons 
C)  neutrinos 
D)  neutrons

Question 14

Sunspots are areas of:

Accepted Answer

A)  strong convection. 
B)  weak convection. 
C)  intense magnetic fields. 
D)  weak magnetic fields. 
A)  strong convection. 
B)  weak convection. 
C)  intense magnetic fields. 
D)  weak magnetic fields.

Question 15

Approximately how long ago was the solar energy we see today produced by fusion?

Accepted Answer

A)  8 minutes 
B)  30 days 
C)  100 years 
D)  105 years 
A)  8 minutes 
B)  30 days 
C)  100 years 
D)  105 years

Question 16

The figure below shows the configuration of magnetic field lines in the Sun at the beginning of a solar magnetic cycle.How do these field lines change as the Sun rotates?

Accepted Answer

Because the Sun's equator rota

Question 17

An astronomer discovers a region on the Sun's surface,roughly the size of Earth,that produces 80% less light than the rest of the Sun's surface.What is the most likely cause of this feature?

Accepted Answer

Intense magnetic fie

Question 18

When energy is carried by photons,astronomers call it:

Accepted Answer

A)  conduction. 
B)  convection. 
C)  radiative energy transport. 
D)  coherence. 
A)  conduction. 
B)  convection. 
C)  radiative energy transport. 
D)  coherence.

Question 19

A blob of gas just above the Sun's radiative zone absorbs energy.How does this energy reach the Sun's surface?

Accepted Answer

The gas rises (becau

Question 20

The figure below shows the proton-proton fusion chain within the Sun.What do the large green dots,small green dots,and large blue dots represent? (Each small "n" represents a neutrino,while each small "g" represents gamma rays.)

Accepted Answer

The large light dots

Why does fusion take place at very high temperatures?

Where does fusion occur in the Sun?

What is the fate of positrons produced through fusion in the Sun's core?

How are oscillations of the Sun's surface measured?

The Sun produces 4 × 10²⁶ joules per second through fusion of hydrogen.How does its mass decrease each second through this process?

Which of the following mechanisms is a result of each and every star in the Universe?

What type of solar activity is shown in the image below?

Which of the following is a result of the solar dynamo?

What happens to a gamma ray photon produced in the Sun's interior as it travels through the radiative zone?

Which of the following lists arranges its constituent nuclei in order from most tightly bound to least tightly bound?

Before 2002,why did astronomers detect only a fraction of the neutrinos they expected from the Sun?

Arrange the following layers of the Sun in order from most to least dense.

The figure below shows the trajectories of particles produced within the Sun.Which kind of particle follows the trajectory labeled "X"?

Sunspots are areas of:

Approximately how long ago was the solar energy we see today produced by fusion?

The figure below shows the configuration of magnetic field lines in the Sun at the beginning of a solar magnetic cycle.How do these field lines change as the Sun rotates?

An astronomer discovers a region on the Sun's surface,roughly the size of Earth,that produces 80% less light than the rest of the Sun's surface.What is the most likely cause of this feature?

When energy is carried by photons,astronomers call it:

A blob of gas just above the Sun's radiative zone absorbs energy.How does this energy reach the Sun's surface?

The figure below shows the proton-proton fusion chain within the Sun.What do the large green dots,small green dots,and large blue dots represent? (Each small "n" represents a neutrino,while each small "g" represents gamma rays.)

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

Measuring the Stars: the Main Sequence and Its Meaning

Nursery of the Stars: the Interstellar Medium and Star Formation

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

Filters

Exam 10: The Sun As a Star

Why does fusion take place at very high temperatures?

Where does fusion occur in the Sun?

What is the fate of positrons produced through fusion in the Sun's core?

How are oscillations of the Sun's surface measured?

The Sun produces 4 × 10²⁶ joules per second through fusion of hydrogen.How does its mass decrease each second through this process?

Which of the following mechanisms is a result of each and every star in the Universe?

What type of solar activity is shown in the image below?

Which of the following is a result of the solar dynamo?

What happens to a gamma ray photon produced in the Sun's interior as it travels through the radiative zone?

Which of the following lists arranges its constituent nuclei in order from most tightly bound to least tightly bound?

Before 2002,why did astronomers detect only a fraction of the neutrinos they expected from the Sun?

Arrange the following layers of the Sun in order from most to least dense.

The figure below shows the trajectories of particles produced within the Sun.Which kind of particle follows the trajectory labeled "X"?

Sunspots are areas of:

Approximately how long ago was the solar energy we see today produced by fusion?

The figure below shows the configuration of magnetic field lines in the Sun at the beginning of a solar magnetic cycle.How do these field lines change as the Sun rotates?

An astronomer discovers a region on the Sun's surface,roughly the size of Earth,that produces 80% less light than the rest of the Sun's surface.What is the most likely cause of this feature?

When energy is carried by photons,astronomers call it:

A blob of gas just above the Sun's radiative zone absorbs energy.How does this energy reach the Sun's surface?

The figure below shows the proton-proton fusion chain within the Sun.What do the large green dots,small green dots,and large blue dots represent? (Each small "n" represents a neutrino,while each small "g" represents gamma rays.)

Getting Started: Science, astronomy, and Being Human

A Universe Made, a Universe Discovered

A Universe of Universal Laws

A Universe of Universal Laws

The Architecture and Birth of Planetary Systems

Home Base: Earth and Moon

Sibling Worlds: Mercury, Venus, and Mars

Gas, ice, and Stone: the Outer Planets

Life and the Search for Habitable Worlds

Measuring the Stars: the Main Sequence and Its Meaning

Nursery of the Stars: the Interstellar Medium and Star Formation

To the Graveyard of Stars: the End Points of Stellar Evolution

Down the Rabbit Hole: Relativity and Black Holes

Our City of Stars: the Milky Way

A Universe of Galaxies

The Cosmic Web: the Large-Scale Structure of the Universe

Cosmology

Filters