Question 1

Sunspots are regions where the Sun's magnetic field penetrates the photosphere. What holds each spot together?

Accepted Answer

A)   the mutual attraction of the magnetic field lines
B)   the attraction of the magnetic field lines for the plasma inside the sunspot
C)   rapid circulation of plasma around the field region
D)   gravitational attraction within the colder, more condensed gases within the spot

Question 2

Spicules on the solar surface are

Accepted Answer

A)   jets of gas surging out of the photosphere of the Sun into the chromosphere, usually at supergranule boundaries.
B)   intense eruptions from sunspot groups and active regions, associated with solar flares.
C)   streams of solar coronal material, usually seen only during a total solar eclipse.
D)   curtainlike structures hanging over sunspot regions.

Question 3

Which of these astronomers was the first to detect the rotation of the Sun by watching sunspot motions?

Accepted Answer

A)   Halley, while watching his comet
B)   Copernicus
C)   Galileo
D)   Ptolemy

Question 4

Which of these is NOT considered to be a feature of the quiet Sun?

Accepted Answer

A)   solar wind
B)   sunspot
C)   spicule
D)   granule

Question 5

During its existence in the Sun's interior, a particular photon experiences

Accepted Answer

A)   only one collision.
B)   thousands of collisions.
C)   millions of collisions.
D)   collisions numbering more than millions.

Question 6

Where is the chromosphere on the Sun?

Accepted Answer

A)   The chromosphere is the outermost part of the Sun's atmosphere.
B)   The chromosphere is the layer below the visible surface of the Sun, where convection begins.
C)   The chromosphere is the visible surface of the Sun.
D)   The chromosphere is the layer above the visible surface of the Sun.

Question 7

By how much does the mass of the Sun decrease each second because of the energy radiated from it (its luminosity) ?

Accepted Answer

A)   6.0 * 1011 kg
B)   2.0 * 107 kg
C)   3.9 *1026 kg
D)   4.3 * 109 kg

Question 8

What is the threshold temperature for the fusion of hydrogen to helium to occur?

Accepted Answer

A)   19,000 K
B)   153,000 K
C)   107 K
D)   1.55 * 107 K

Question 9

The sunspot cycle on the Sun is a(n)

Accepted Answer

A)   regular movement of a relatively constant number of sunspots from the poles to the equator of the Sun over an 11-year period.
B)   somewhat irregular cycle of buildup and decay of sunspot numbers, averaging about 11 years and with a variable number of sunspots for each cycle.
C)   extremely regular buildup and decay in the number of sunspots, with a precise period of 11 years but with widely varying numbers of sunspots
D)   Extremely regular buildup and decay in the number of sunspots, with a precise period of 11 years with every cycle having the same number of sunspots at maximum.

Question 10

The Stefan-Boltzmann law indicates that the energy emitted per second per area of an emitting surface varies with the fourth power of the Kelvin temperature. Suppose the center of a sunspot on the Sun's photosphere is 4000 K and the normal photosphere is about 6000 K. About how much energy is emitted each second from each unit area in the center of this sunspot compared with that from the normal photosphere?

Accepted Answer

A)   10-8
B)   0.20
C)   0.67
D)   0.98

Question 11

Mean temperatures in Europe during the Maunder minimum, when virtually no sunspots were seen between 1645 and 1715, were

Accepted Answer

A)   more strongly fluctuating above and below the average temperature compared with the period from 1715 to the present.
B)   unchanged, within statistical uncertainty.
C)   higher than average.
D)   lower than average.

Question 12

What change in spectral lines emitted by atoms is described by the Zeeman effect?

Accepted Answer

A)   broadening of the lines associated with the high temperature of the emitting gas
B)   change in relative intensity of different lines from sources of different temperature
C)   shift in the lines because of the movement of the source
D)   splitting of lines because the atoms are within an intense magnetic field

Question 13

The Stefan-Boltzmann law indicates that the energy emitted per second per area of an emitting surface varies with the fourth power of the Kelvin temperature. Suppose the center of a granule on the Sun's photosphere is 6000 K and the edges of the cell are 100 K cooler. About how much energy is emitted each second from each unit area on the edge compared with that from the center?

Accepted Answer

A)   10-8
B)   50%
C)   93%
D)   127%

Question 14

How does the average density of the Sun compare with that of the planet Jupiter?

Accepted Answer

A)   It is not possible to specify an average density for an object as large as the Sun.
B)   The Sun is many times denser than Jupiter.
C)   The Sun is considerably less dense than Jupiter.
D)   The Sun has approximately the same average density as Jupiter.

Question 15

The two most important processes by which energy is transported from the core of the Sun to the photosphere are

Accepted Answer

A)   conduction and convection.
B)   radiation and convection.
C)   radiation and conduction.
D)   radiation and neutrino emission.

Question 16

The Sun has nearly the same temperature today that it had 4.5 billion years ago, but it is now 30% more luminous. Why?

Accepted Answer

A)   The Sun has a stronger magnetic field today.
B)   The Sun has a larger surface area today.
C)   The Sun has more sunspots today.
D)   Energy took longer to escape the young Sun.

Question 17

How much hydrogen is converted to helium each second in the Sun?

Accepted Answer

A)   6 billion tons
B)   600 tons
C)   6 tons
D)   600 million tons

Question 18

The core of the Sun, in which the Sun's thermonuclear energy is produced, takes up about

Accepted Answer

A)   1/2 the Sun's radius.
B)   1/4 of the Sun's radius.
C)   less than 1/100 of the Sun's radius.
D)   1/10 of the Sun's radius.

Question 19

What is the name of a sudden, highly energetic, eruptive surge on the surface of the Sun?

Accepted Answer

A)   prominence
B)   sunspot
C)   plage
D)   flare

Question 20

Where is the coolest region in the Sun?

Accepted Answer

A)   just below the photosphere, in the convective zone
B)   in the lower corona
C)   in the lower photosphere
D)   in the lower chromosphere

Exam 11: The Sun: Our Extraordinary Star

During its existence in the Sun's interior, a particular photon experiences

Correct Answer
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Correct Answer
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By how much does the mass of the Sun decrease each second because of the energy radiated from it (its luminosity) ?

Correct Answer
verified

The core of the Sun, in which the Sun's thermonuclear energy is produced, takes up about

Correct Answer
verified

Which of these is NOT considered to be a feature of the quiet Sun?

Correct Answer
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What change in spectral lines emitted by atoms is described by the Zeeman effect?

Correct Answer
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Sunspots are regions where the Sun's magnetic field penetrates the photosphere. What holds each spot together?

Correct Answer
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Spicules on the solar surface are

Correct Answer
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Where is the chromosphere on the Sun?

Correct Answer
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Where is the coolest region in the Sun?

Correct Answer
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The sunspot cycle on the Sun is a(n)

Correct Answer
verified

The Sun has nearly the same temperature today that it had 4.5 billion years ago, but it is now 30% more luminous. Why?

Correct Answer
verified

Mean temperatures in Europe during the Maunder minimum, when virtually no sunspots were seen between 1645 and 1715, were

Correct Answer
verified

Correct Answer
verified

What is the threshold temperature for the fusion of hydrogen to helium to occur?

Correct Answer
verified

What is the name of a sudden, highly energetic, eruptive surge on the surface of the Sun?

Correct Answer
verified

How much hydrogen is converted to helium each second in the Sun?

Correct Answer
verified

The two most important processes by which energy is transported from the core of the Sun to the photosphere are

Correct Answer
verified

Which of these astronomers was the first to detect the rotation of the Sun by watching sunspot motions?

Correct Answer
verified

How does the average density of the Sun compare with that of the planet Jupiter?

Correct Answer
verified

Exam 11: The Sun: Our Extraordinary Star

During its existence in the Sun's interior, a particular photon experiences

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

By how much does the mass of the Sun decrease each second because of the energy radiated from it (its luminosity) ?

Correct AnswerverifiedShow Answer

The core of the Sun, in which the Sun's thermonuclear energy is produced, takes up about

Correct AnswerverifiedShow Answer

Which of these is NOT considered to be a feature of the quiet Sun?

Correct AnswerverifiedShow Answer

What change in spectral lines emitted by atoms is described by the Zeeman effect?

Correct AnswerverifiedShow Answer

Sunspots are regions where the Sun's magnetic field penetrates the photosphere. What holds each spot together?

Correct AnswerverifiedShow Answer

Spicules on the solar surface are

Correct AnswerverifiedShow Answer

Where is the chromosphere on the Sun?

Correct AnswerverifiedShow Answer

Where is the coolest region in the Sun?

Correct AnswerverifiedShow Answer

The sunspot cycle on the Sun is a(n)

Correct AnswerverifiedShow Answer

The Sun has nearly the same temperature today that it had 4.5 billion years ago, but it is now 30% more luminous. Why?

Correct AnswerverifiedShow Answer

Mean temperatures in Europe during the Maunder minimum, when virtually no sunspots were seen between 1645 and 1715, were

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

What is the threshold temperature for the fusion of hydrogen to helium to occur?

Correct AnswerverifiedShow Answer

What is the name of a sudden, highly energetic, eruptive surge on the surface of the Sun?

Correct AnswerverifiedShow Answer

How much hydrogen is converted to helium each second in the Sun?

Correct AnswerverifiedShow Answer

The two most important processes by which energy is transported from the core of the Sun to the photosphere are

Correct AnswerverifiedShow Answer

Which of these astronomers was the first to detect the rotation of the Sun by watching sunspot motions?

Correct AnswerverifiedShow Answer

How does the average density of the Sun compare with that of the planet Jupiter?

Correct AnswerverifiedShow Answer

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