Question 1

The solar wind is

Accepted Answer

A)  the flow of matter onto the Sun under gravitational attraction. 
B)  ionized hydrogen gas and electrons orbiting the Sun between its surface and the planet Mercury. 
C)  a violent, explosive expansion of specific regions of the Sun's atmosphere at certain times. 
D)  a gentle flow of solar material, mostly protons and electrons, that is always moving outward from the Sun. 
A)  the flow of matter onto the Sun under gravitational attraction. 
B)  ionized hydrogen gas and electrons orbiting the Sun between its surface and the planet Mercury. 
C)  a violent, explosive expansion of specific regions of the Sun's atmosphere at certain times. 
D)  a gentle flow of solar material, mostly protons and electrons, that is always moving outward from the Sun.

Question 2

Which of these particles or types of radiation will provide the MOST direct information on the processes of nuclear fusion that are occurring at the present time in the solar core?

Accepted Answer

A)  X-rays from the solar corona 
B)  protons in the solar wind and from solar flares 
C)  neutrinos 
D)  visible light from the photosphere 
A)  X-rays from the solar corona 
B)  protons in the solar wind and from solar flares 
C)  neutrinos 
D)  visible light from the photosphere

Question 3

The visible light coming from the solar chromosphere is dominated by light of what color?

Accepted Answer

A)  indigo 
B)  blue 
C)  green 
D)  red 
A)  indigo 
B)  blue 
C)  green 
D)  red

Question 4

Which of these phenomena is NOT a characteristic of the peak period in the solar activity cycle?

Accepted Answer

A)  increased surface temperature on the Sun and a measurable increase in the temperature of Earth's atmosphere 
B)  increased solar flare activity with consequent disruption of radio communications on Earth 
C)  stronger magnetic field on the Sun and increased numbers of sunspots 
D)  enhanced aurora activity on Earth 
A)  increased surface temperature on the Sun and a measurable increase in the temperature of Earth's atmosphere 
B)  increased solar flare activity with consequent disruption of radio communications on Earth 
C)  stronger magnetic field on the Sun and increased numbers of sunspots 
D)  enhanced aurora activity on Earth

Question 5

What fraction of the Sun's total emission, across all wavelengths, is produced by the corona?

Accepted Answer

A)  one part in a trillion 
B)  one part in a million 
C)  one percent 
D)  about one-third 
A)  one part in a trillion 
B)  one part in a million 
C)  one percent 
D)  about one-third

Question 6

Nuclear fusion is the

Accepted Answer

A)  combining of electrons with nuclei to produce atoms and release energy. 
B)  splitting of heavier nuclei to produce lighter nuclei and energy. 
C)  combining of hydrogen atoms to produce hydrogen molecules, H2, and energy. 
D)  combining of light nuclei (e.g., hydrogen) to produce heavier nuclei (e.g., helium) with a resultant release of energy. 
A)  combining of electrons with nuclei to produce atoms and release energy. 
B)  splitting of heavier nuclei to produce lighter nuclei and energy. 
C)  combining of hydrogen atoms to produce hydrogen molecules, H2, and energy. 
D)  combining of light nuclei (e.g., hydrogen) to produce heavier nuclei (e.g., helium) with a resultant release of energy.

Question 7

How can astronomers BEST observe the 5-minute oscillations of the Sun's surface?

Accepted Answer

A)  Zeeman-effect measurements of magnetically sensitive lines 
B)  high-resolution positional observations of the edge of the solar disk 
C)  measurement of the modulation of radio emissions from the solar surface, similar to the modulation used to transmit sound signals by radio on Earth 
D)  high-precision Doppler shifts of spectral lines 
A)  Zeeman-effect measurements of magnetically sensitive lines 
B)  high-resolution positional observations of the edge of the solar disk 
C)  measurement of the modulation of radio emissions from the solar surface, similar to the modulation used to transmit sound signals by radio on Earth 
D)  high-precision Doppler shifts of spectral lines

Question 8

The corona of the Sun has a temperature that is

Accepted Answer

A)  about 10 K because it merges with cold interstellar space. 
B)  noticeably less than the photosphere, between 1000 to 2000 K. 
C)  about 1 to 2 million K. 
D)  about the same as the photosphere, about 6000 K. 
A)  about 10 K because it merges with cold interstellar space. 
B)  noticeably less than the photosphere, between 1000 to 2000 K. 
C)  about 1 to 2 million K. 
D)  about the same as the photosphere, about 6000 K.

Question 9

The solar wind is strongest

Accepted Answer

A)  near the solar equator, where solar spin reduces the gravitational field. 
B)  in flare explosions. 
C)  in sunspots. 
D)  in coronal holes, cooler, lower-density regions in the corona. 
A)  near the solar equator, where solar spin reduces the gravitational field. 
B)  in flare explosions. 
C)  in sunspots. 
D)  in coronal holes, cooler, lower-density regions in the corona.

Question 10

What is the main source of the energy radiated by the Sun?

Accepted Answer

A)  Chemical reactions combine hydrogen and helium to produce energy. 
B)  Protons are destroyed and converted into pure energy as described by Einstein's mass-energy relationship. 
C)  Small nuclei combine to form larger nuclei with a consequent release of energy. 
D)  gravitational collapse as described by the Kelvin-Helmholtz contraction 
A)  Chemical reactions combine hydrogen and helium to produce energy. 
B)  Protons are destroyed and converted into pure energy as described by Einstein's mass-energy relationship. 
C)  Small nuclei combine to form larger nuclei with a consequent release of energy. 
D)  gravitational collapse as described by the Kelvin-Helmholtz contraction

Question 11

Which of these BEST describes the net fusion reaction powering the Sun?

Accepted Answer

A)  4 He $\implies$O 
B)  2 H $\implies$ He 
C)  3 He $\implies$ C 
D)  4 H $\implies$He 
A)  4 He $\implies$O 
B)  2 H $\implies$ He 
C)  3 He $\implies$ C 
D)  4 H $\implies$He

Question 12

Compared with the dimensions of a granule in the Sun's photosphere, a supergranule in the chromosphere is

Accepted Answer

A)  very much larger; the diameter of each supergranule spreads across about a million granules. 
B)  a little larger, by a factor of 2. 
C)  much larger, by a factor of about 1000. 
D)  larger, by a factor of 10. 
A)  very much larger; the diameter of each supergranule spreads across about a million granules. 
B)  a little larger, by a factor of 2. 
C)  much larger, by a factor of about 1000. 
D)  larger, by a factor of 10.

Question 13

Just outside the radiative zone of the Sun lies the

Accepted Answer

A)  convection zone. 
B)  conduction zone. 
C)  photosphere. 
D)  corona. 
A)  convection zone. 
B)  conduction zone. 
C)  photosphere. 
D)  corona.

Question 14

The centers of the granular cells on the surface of the Sun appear to be brighter than the edges of the cells because

Accepted Answer

A)  higher magnetic field strength at the centers condenses and heats the gases there. 
B)  the centers are composed of gases that are different from the gases that compose the edges. 
C)  gases at the centers are more transparent than gases at the edges, allowing astronomers to view deeper and hotter layers. 
D)  the centers are hotter than the edges. 
A)  higher magnetic field strength at the centers condenses and heats the gases there. 
B)  the centers are composed of gases that are different from the gases that compose the edges. 
C)  gases at the centers are more transparent than gases at the edges, allowing astronomers to view deeper and hotter layers. 
D)  the centers are hotter than the edges.

Question 15

What is the Zeeman effect?

Accepted Answer

A)  When a light source is moving relative to an observer, the wavelengths of its spectral lines are shifted to longer or shorter wavelengths. 
B)  When the temperature of a light source is increased, the wavelength of maximum emission decreases. 
C)  When a light source is located in a magnetic field, the emitted spectral lines are split into two or more components. 
D)  When light is focused on a metal surface, electrons are ejected from the metal only if the wavelength of the light is shorter than some critical wavelength. 
A)  When a light source is moving relative to an observer, the wavelengths of its spectral lines are shifted to longer or shorter wavelengths. 
B)  When the temperature of a light source is increased, the wavelength of maximum emission decreases. 
C)  When a light source is located in a magnetic field, the emitted spectral lines are split into two or more components. 
D)  When light is focused on a metal surface, electrons are ejected from the metal only if the wavelength of the light is shorter than some critical wavelength.

Question 16

In carrying energy through the interior of the Sun, there are many collisions between particles (photons, ions, atoms). What is the net direction of the energy flow in these collisions?

Accepted Answer

A)  The collisions are random, the energy flows equally in all directions, and it is only by chance that some photons carry energy out of the Sun. 
B)  The collisions generally result in energy flow from the core, where temperatures are higher and the particles are moving faster, toward the outer layers where temperatures are lower and particles are moving more slowly. 
C)  The collisions generally result in energy flow from the core, where particles are more massive and thus carrying more energy, toward the outer layers where particles are less massive and thus carry less energy. 
D)  Because of the higher temperatures toward the core, the particles there are mostly ionized. The electric charge of these ionized particles repels particles from farther out from penetrating the core. Thus, energy flow is primarily outward. 
A)  The collisions are random, the energy flows equally in all directions, and it is only by chance that some photons carry energy out of the Sun. 
B)  The collisions generally result in energy flow from the core, where temperatures are higher and the particles are moving faster, toward the outer layers where temperatures are lower and particles are moving more slowly. 
C)  The collisions generally result in energy flow from the core, where particles are more massive and thus carrying more energy, toward the outer layers where particles are less massive and thus carry less energy. 
D)  Because of the higher temperatures toward the core, the particles there are mostly ionized. The electric charge of these ionized particles repels particles from farther out from penetrating the core. Thus, energy flow is primarily outward.

Question 17

What is a plasma?

Accepted Answer

A)  region where the H $\alpha$ line causes the Sun's surface to glow red, like blood 
B)  region where the intense magnetic field has caused the Sun's atoms to line up in a rigid array 
C)  gaslike mixture of ions and electrons 
D)  unusual mixture of charged particles in which the positives and negatives do not occur in equal numbers 
A)  region where the H $\alpha$ line causes the Sun's surface to glow red, like blood 
B)  region where the intense magnetic field has caused the Sun's atoms to line up in a rigid array 
C)  gaslike mixture of ions and electrons 
D)  unusual mixture of charged particles in which the positives and negatives do not occur in equal numbers

Question 18

The magnetic field in a large rotating body can reverse direction periodically. For which two bodies in the solar system has evidence been found for such magnetic reversals?

Accepted Answer

A)  Sun and Moon 
B)  Sun and Earth 
C)  Earth and Moon 
D)  Earth and Venus 
A)  Sun and Moon 
B)  Sun and Earth 
C)  Earth and Moon 
D)  Earth and Venus

Question 19

Astronomers use the word "limb" to refer to what part of a celestial body?

Accepted Answer

A)  edge 
B)  center 
C)  top 
D)  bottom 
A)  edge 
B)  center 
C)  top 
D)  bottom

Question 20

What is the rotation period of the Sun?

Accepted Answer

A)  about 2 rotations per year 
B)  about 1 rotation per day 
C)  about 4 rotations per month 
D)  about 1 rotation per month 
A)  about 2 rotations per year 
B)  about 1 rotation per day 
C)  about 4 rotations per month 
D)  about 1 rotation per month

The solar wind is

Which of these particles or types of radiation will provide the MOST direct information on the processes of nuclear fusion that are occurring at the present time in the solar core?

The visible light coming from the solar chromosphere is dominated by light of what color?

Which of these phenomena is NOT a characteristic of the peak period in the solar activity cycle?

What fraction of the Sun's total emission, across all wavelengths, is produced by the corona?

Nuclear fusion is the

How can astronomers BEST observe the 5-minute oscillations of the Sun's surface?

The corona of the Sun has a temperature that is

The solar wind is strongest

What is the main source of the energy radiated by the Sun?

Which of these BEST describes the net fusion reaction powering the Sun?

Compared with the dimensions of a granule in the Sun's photosphere, a supergranule in the chromosphere is

Just outside the radiative zone of the Sun lies the

The centers of the granular cells on the surface of the Sun appear to be brighter than the edges of the cells because

What is the Zeeman effect?

In carrying energy through the interior of the Sun, there are many collisions between particles (photons, ions, atoms). What is the net direction of the energy flow in these collisions?

What is a plasma?

The magnetic field in a large rotating body can reverse direction periodically. For which two bodies in the solar system has evidence been found for such magnetic reversals?

Astronomers use the word "limb" to refer to what part of a celestial body?

What is the rotation period of the Sun?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters

Exam 11: The Sun: Our Extraordinary Star

The solar wind is

Which of these particles or types of radiation will provide the MOST direct information on the processes of nuclear fusion that are occurring at the present time in the solar core?

The visible light coming from the solar chromosphere is dominated by light of what color?

Which of these phenomena is NOT a characteristic of the peak period in the solar activity cycle?

What fraction of the Sun's total emission, across all wavelengths, is produced by the corona?

Nuclear fusion is the

How can astronomers BEST observe the 5-minute oscillations of the Sun's surface?

The corona of the Sun has a temperature that is

The solar wind is strongest

What is the main source of the energy radiated by the Sun?

Which of these BEST describes the net fusion reaction powering the Sun?

Compared with the dimensions of a granule in the Sun's photosphere, a supergranule in the chromosphere is

Just outside the radiative zone of the Sun lies the

The centers of the granular cells on the surface of the Sun appear to be brighter than the edges of the cells because

What is the Zeeman effect?

In carrying energy through the interior of the Sun, there are many collisions between particles (photons, ions, atoms). What is the net direction of the energy flow in these collisions?

What is a plasma?

The magnetic field in a large rotating body can reverse direction periodically. For which two bodies in the solar system has evidence been found for such magnetic reversals?

Astronomers use the word "limb" to refer to what part of a celestial body?

What is the rotation period of the Sun?

Discovering the Night Sky

Gravitation and the Motion of the Planets

Light and Telescopes

Atomic Physics and Spectra

Exoplanets and the Formation of Planetary Systems

Formation of the Solar System

Earth and the Moon

The Other Terrestrial Planets

The Outer Planets

Vagabonds of the Solar System

Characterizing Stars

The Lives of Stars From Birth Through Middle Age

The Death of Stars

Black Holes: Matters of Gravity

The Milky Way Galaxy

Galaxies

Quasars and Other Active Galaxies

Cosmology

Astrobiology

Filters