chapter 9

Question 1

Granulation on the surface of the Sun is caused by:

• differential rotation of the Sun.
• nuclear fusion processes occurring just below the surface.
• magnetic field disturbances above the solar surface.
• convective currents carrying heat from beneath the surface.

Answer 1

convective currents carrying heat from beneath the surface.

Question 2

Sunspots are:

• cooler, darker regions on the Sun’s surface.
• hotter, deeper regions in the Sun’s atmosphere.
• cooler regions of the Sun’s high corona.
• the shadows of cool, dark curtains of matter, hanging above the solar surface.

Answer 2

cooler, darker regions on the Sun’s surface.

Question 3

What process provides the power for the Sun?

• The fission of uranium to form lead.
• The fusion of helium into carbon.
• The fusion of hydrogen into helium.
• The emission of neutrinos.

Answer 3

The fusion of hydrogen into helium.

Question 4

What are the names of the three layers in the Sun’s atmosphere, in order from highest to lowest?

• Photosphere, corona, chromosphere.
• Photosphere, chromosphere, corona.
• Chromosphere, photosphere, corona.
• Corona, chromosphere, photosphere.

Answer 4

Corona, chromosphere, photosphere.

Question 5

The _________________________ is then given by the sum of the number of individual sunspots and ten times the number of groups.

• Jeans density
• Wiens factor
• sunspot number
• Reynolds number

Answer 5

sunspot number

Question 6

__________________ are regions of higher temperature and density surrounding sunspots.

• Plages.
• Flares.
• Corona.
• Photosphere.

Answer 6

Plages.

Question 7

The layer of the sun that is normally visible to us is the:

• corona
• chromosphere
• photosphere
• core

Answer 7

photosphere

Question 8

What is a spicule on the Sun?

• A bright arc of gas suspended above the edge of the visible disk of the Sun.
• A long, thin, curved line of bright gas in the corona.
• A small, bright cell in the photosphere.
• A jet of rising gas in the chromosphere.

Answer 8

A jet of rising gas in the chromosphere.

Question 9

The Sun’s energy is generated by:

• gravitational contraction
• nuclear fission
• nuclear fusion
• chemical reactions

Answer 9

nuclear fusion

Question 10

The thickness of the photosphere, or the visible “surface” of the Sun, is:

• several times 10,000 km.
• about 4000 km.
• about 400 km.
• only about 1 km.

Answer 10

about 400 km.

Question 11

How does the Sun’s overall magnetic field behave?

• The Sun does not have an overall coherent field but magnetic fields, their polarity is centered upon sunspots and randomly distributed over the Sun.
• The northern and southern hemispheres have the same magnetic polarity, and this polarity reverses every 11 years.
• The northern and southern hemispheres have opposite magnetic polarity, and this polarity reverses every 11 years.
• The poles of the Sun have the opposite magnetic polarity from the equator, and this polarity reverses every 11 years.

Answer 11

The northern and southern hemispheres have opposite magnetic polarity, and this polarity reverses every 11 years.

Question 12

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

• A sunspot.
• A prominence.
• A plage.
• A flare.

Answer 12

a flare

Question 13

Sunspots are areas on the sun that are:

• hotter than their surroundings.
• cooler than their surroundings.
• rivers of lava.
• rivers of steam.

Answer 13

cooler than their surroundings.

Question 14

What is the character of the sunspot cycle?

• Starting at sunspot minimum, new spots appear uniformly over the Sun, then gradually become concentrated at mid-latitudes as they increase and then decrease in number.
• Starting at sunspot minimum, spots first appear far from the equator, followed by new spots appearing closer to the equator as they increase in number, then die out close to the equator.
• Sunspots increase and decrease in number over 11 years, appearing at random locations between latitudes 10° and 30° from the equator in both hemispheres.
• Starting at sunspot minimum, new spots appear close to the equator, followed by spots appearing farther from the equator as they increase in number, the latest spots dying out at high latitudes.

Answer 14

Starting at sunspot minimum, spots first appear far from the equator, followed by new spots appearing closer to the equator as they increase in number, then die out close to the equator.

Question 15

The _____________ is the Sun’s outer atmosphere. It is visible during total eclipses of the Sun as a pearly white crown surrounding the Sun.

• corona.
• chromosphere.
• photosphere.
• core.

Answer 15

corona

Question 16

The surface of the Sun is divided into light-colored areas with dark boundaries in a cellular pattern. What are these cells called?

• Sunspots.
• Granules.
• Filaments.
• Spicules.

Answer 16

Granules.

Question 17

What is the solar wind?

• The circulation of gases between the equator and the poles of the Sun.
• The constant flux of photons from the Sun’s visible surface.
• The Sun’s outer atmosphere streaming out into space.
• The storm of waves and vortices on the Sun’s surface generated by a solar flare.

Answer 17

The Sun’s outer atmosphere streaming out into space.

Question 18

The two forces producing hydrostatic equilibrium in the sun are:

• electrical forces and gravity.
• nuclear forces and gravity.
• electrical forces and gas pressure.
• gravity and gas pressure.

Answer 18

nuclear forces and gravity.

Question 19

Where is the coolest region in the Sun?

• In the lower corona.
• In the photosphere.
• In the convective zone.
• In the lower chromosphere.

Answer 19

In the photosphere.

Question 20

Where is the chromosphere on the Sun?

• It is the outermost part of the Sun’s atmosphere.
• It is the layer below the visible surface of the Sun, where convection begins.
• It is the visible surface of the Sun.
• It is the layer above the visible surface of the Sun

Answer 20

It is the layer above the visible surface of the Sun

Question 21

Energy is transported from the center of the Sun to the surface by:

• mostly convection; radiation only in the outer layers.
• convection in the thermonuclear core; radiation everywhere else.
• mostly radiation; convection only in the outer layers.
• radiation in the thermonuclear core; convection everywhere else.

Answer 21

mostly radiation; convection only in the outer layers.

Question 22

Sunspots are caused by:

• the impact of meteoroids and comets on the solar surface.
• differential rotation and its effect on weak magnetic fields just under the solar surface.
• dark, absorbing clouds hanging over the surface, above the magnetic field regions.
• coronal holes, which darken the surface.

Answer 22

differential rotation and its effect on weak magnetic fields just under the solar surface.

Question 23

What is the photosphere of the Sun?

• The core of the Sun, where nuclear energy is generated.
• The visible “surface” of the Sun.
• The middle layer of the Sun’s atmosphere.
• The region of convecting gases below the visible surface of the Sun.

Answer 23

The visible “surface” of the Sun.

Question 24

The gas motions within granules on the solar surface are:

• upward in the centers of some cells and downward in the centers of others; the gas cools as it passes over the boundaries between cells.
• upward flow in the bright cell centers and downward flow around the darker edges.
• downward flow in the bright cell centers and upward flow around the darker edges.
• almost non-existent; the dark patterns represent a network of absorbing gases overlying the photosphere.

Answer 24

upward flow in the bright cell centers and downward flow around the darker edges.