Deck 8: The Sun

Question 1

Sunspots are known to be magnetic phenomena because

A) Doppler shifts in spectral lines are observed.
B) the Zeeman Effect is observed in sunspots.
C) collisional broadening is observed in spectral lines.
D) infrared observations indicate that the sunspots are cooler than their surroundings.
E) observations during eclipses reveal a very extensive photosphere.

Answer 1

the Zeeman Effect is observed in sunspots.

Question 2

____ occur(s)because photons we receive from the edge of the solar disk are emitted further from the base of the photosphere than the photons we receive from the center of the solar disk.

A) The Zeeman Effect
B) Sunspots
C) Solar flares
D) Solar prominences
E) Limb darkening

Answer 2

Limb darkening

Question 3

Modern astronomers suspect the corona is heated by

A) shock waves rising from below the photosphere.
B) the solar wind.
C) the solar magnetic field.
D) all of these
E) none of these

Answer 3

the solar magnetic field.

Question 4

The corona of the sun can be observed

A) during a lunar eclipse.
B) with a coronagraph.
C) using filtergrams.
D) a and b above
E) with none of the above

Question 5

Sunspots are dark because

A) regions of the photosphere are obscured by material in the chromosphere.
B) shock waves move through the photosphere.
C) the sun rotates differentially.
D) the strong magnetic field inhibits the currents of hot gas rising from below.
E) they radiate their energy into space faster than the rest of the photosphere.

Question 6

The diagram below shows a plot of the temperature of the sun as a function of distance above the bottom of the photosphere.At what distance above the bottom of the photosphere does the temperature of the sun change the most rapidly with distance?

A) 1,000 km
B) 2,300 km
C) 2,500 km to 4,000 km
D) 500 km
E) a and c

Question 7

The energy generated by the sun is released by the ____ to make ____ nuclei.

A) fusion of H nuclei,He
B) fusion of He nuclei,H
C) fission of H nuclei,He
D) fission of He nuclei,H

Question 8

Fusion is promoted in the core of the sun by the ____ there.

A) low temperature and low density
B) high temperature and high density
C) low temperature and high density
D) high temperature and low density

Question 9

Most of the energy emitted by the sun is generated in the

A) corona.
B) photosphere.
C) chromosphere.
D) core.

Question 10

Neutrinos are created in reactions in the ____ of the sun.

A) corona
B) chromosphere
C) photosphere
D) core

Question 11

Granulation is caused by

A) sunspots.
B) rising gas below the photosphere.
C) shock waves in the corona.
D) the solar wind flowing away from the corona.
E) the heating in the chromosphere.

Question 12

Sunspots

A) are hotter than their surroundings.
B) are regions where material is rising from below the photosphere.
C) show the Zeeman effect indicating the presence of strong magnetic fields.
D) produce spicules.
E) are generally found near the poles of the sun during sunspot maximum.

Question 13

The centers of granules

A) are hot material rising to the photosphere from below.
B) are cool material falling from the photosphere to the regions below.
C) are fainter and hotter than their surroundings.
D) are brighter and cooler than their surroundings.
E) show strong Zeeman effects.

Question 14

The ____ is(are)the hot gases that are the moving extension of the sun's corona.

A) spicules
B) prominences
C) flares
D) supergranules
E) solar wind

Question 15

A filtergram is a photograph of the sun's surface made

A) in a band of wavelengths in the infrared.
B) in a band of wavelengths in the ultraviolet.
C) using the Zeeman Effect.
D) with only those photons emitted in a specific spectral line.
E) none of the above

Question 16

In some regions of the corona,the magnetic field does not loop back to the sun,and the gas escapes unimpeded.These regions are called ____ and are believed to be the source of the solar wind.

A) prominences
B) flares
C) granules
D) auroras
E) coronal holes

Question 17

The intensity of a sunspot is found to be 3 times smaller than the intensity emitted by the solar surface.What is the approximate temperature of this sunspot if the temperature of the solar surface is 5,800 K?

A) 4,400 K
B) 470,000 K
C) 1,900 K
D) 7,600 K
E) 1,400 K

Question 18

High temperatures are required to get H nuclei to fuse because they ____ one another because of their ____ electric charges.

A) attract,negative
B) attract,positive
C) repel,negative
D) repel,positive

Question 19

The photosphere is very thin because

A) the temperature of the photosphere increases rapidly from its base to its outer edge.
B) the gas bubbles that form the granulation pattern cannot travel very far.
C) the magnetic field compresses the photosphere.
D) the H ^- ion is a very good absorber of photons and causes the gas of the photosphere to be opaque.
E) the sun rotates differentially.

Question 20

Most of the light we see coming from the sun originates in the

A) chromosphere.
B) photosphere.
C) corona.
D) sunspots.
E) magnetic field.

Question 21

What is the explanation for the pattern of granulation seen on the visible surface of the Sun?

A) The granules form the base of a circulation pattern that extends from the photosphere to the outer corona.
B) The granules are regions of nuclear energy generation in the Sun's photosphere.
C) Each granule contains a strong magnetic field,which compresses and heats the gas underneath it.
D) The granules are the tops of hot gas that have risen from the Sun's convective zone.

Question 22

If a sunspot has a temperature of 4,500 K and the surrounding solar surface has a temperature of 5,800 K,how many times brighter is the surface compared to the sunspot?

A) 0.28
B) 0.36
C) 2.8
D) 3.6
E) 36

Question 23

The most recent sunspot maximum occurred in 2001.When is the next sunspot maximum expected if the solar cycle continues?

A) 1990
B) 2006
C) 2012
D) 2023
E) The last cycle started a Maunder minimum,and the next maximum can not be predicted.

Question 24

The capture of too few solar neutrinos by Davis in the solar neutrino experiment

A) was disproved by the results of later experiments.
B) can be explained if the sun is not undergoing thermonuclear fusion of hydrogen in its core.
C) indicates that the sun's core is much hotter than expected.
D) indicates the sun's core is convective.
E) none of the above

Question 25

Spicules

A) are found in the photosphere.
B) are magnetic disturbances that push large loops of material off the solar surface.
C) are responsible for twisting the solar magnetic field and causing the sunspot cycle.
D) appear in the corona near the north and south poles of the sun during a total solar eclipse.
E) are visible in filtergrams of the solar chromosphere.

Question 26

The sunspot cycle affects

A) I & II
B) I & IV
C) II & III
D) I,II & III
E) I,II,& IV

Question 27

The gas motions within granules on the solar surface are

A) upward in the centers of some cells and downward in others; the gas cools as it passes between individual granules.
B) actually motionless.The dark regions are absorption features from gases in the photosphere.
C) upward in the bright cell centers and downward around the darker edges.
D) downward in the bright cell centers and upward around the darker edges.

Question 28

The solar constant is a measure of

A) the amount of solar energy reaching the earth.
B) the length of the sunspot cycle.
C) the period of rotation of the sun's equator.
D) the average number of sunspots seen during the Maunder minimum.
E) the sun's mass.

Question 29

The figure shows the sun and pairs of sunspots.One could say that there is really a 22 year sunspot cycle because ...

A) the time between sunspot number maxima is 22 years.
B) the time between maxima of the same magnetic polarity of sunspot pairs is 22 years.
C) it takes sunspots 22 years to move from the poles to the equator.
D) at maximum there are 22 sunspots per year.

Question 30

The sun's magnetic field is evident in the looped shapes of

A) solar flares.
B) sunspots.
C) the corona.
D) granules.
E) solar prominences.

Question 31

What are the three layers of the Sun's atmosphere,in order of increasing distance from the surface?

A) Corona,chromosphere,photosphere
B) Photosphere,corona,chromosphere
C) Photosphere,chromosphere,corona
D) Chromosphere,photosphere,corona

Question 32

Why is the temperature at the region of a sunspot cooler than the photosphere?

A) They are holes in the photosphere that reveal the lower temperature gases in the deeper layers.
B) They represent points where streams of cool gas from the corona lower the temperature in those regions of the photosphere
C) Powerful magnetic fields in the sunspots act upon the atoms of the photosphere to prevent them from emitting light.
D) Powerful magnetic fields inhibit the convective flow of the gases of the photosphere allowing them to cool for longer than would normally be permitted.

Question 33

The United States consumes 2.5*10¹⁹ J of energy each year.A typical solar flare releases 5.0*10²⁴ J of energy.How many years could we run the United States on the energy released by this solar flare if all of the released energy could be used?

A) 5*^-6 years
B) 200,000 years
C) 1.25*10⁴⁴ years
D) about 12 years
E) 500 years

Question 34

What evidence supports the contention that other sun-like stars also show a spot cycle much like our sun's sunspot cycle?

A) the variation in the rotation rates of sun-like stars
B) the variation in the nuclear reaction rates in sun-like stars
C) the variation in the strength of the H and K emissions in the spectra of sun-like stars
D) the variation in the parallax of sun-like stars
E) the variation in the color of sun-like stars

Question 35

If one kilogram of hydrogen is converted to helium,how much energy will be generated?

A) 9*10¹⁶ J
B) 3*10⁸ J
C) 6.5*10¹⁴ J
D) 2.2*10⁶ J
E) 3.2*10⁷ J

Question 36

The Zeeman effect can be used to determine the _______ our sun and other stars.

A) rotation speed of
B) mass of
C) color of
D) magnetic field on
E) radial velocity toward or away from

Question 37

The variation in the strength of the calcium H and K emission from sun-like stars implies that these stars

A) probably have very extended coronae.
B) probably have a magnetic cycle similar to the sun's.
C) do not rotate differentially.
D) may have planets that orbit them.
E) probably have supergranules and spicules.

Question 38

If the spectrum of a sunspot shows that it has a maximum intensity at 650 nm,what is the temperature of the sunspot?

A) 650 K
B) 5000 K
C) 1950 K
D) 4600 K
E) 10,000 K

Question 39

A ____ is believed to occur when energy,stored in a twist in the solar magnetic field above a sunspot,is suddenly released.

A) solar flare
B) supergranule
C) spicule
D) coronal hole
E) none of the above

Question 40

The rotation of the Sun is

A) fastest at the equator,slower at mid-latitudes,and slowest near the poles.
B) slowest at the equator,faster at mid-latitudes,and fastest near the poles.
C) fastest at the equator,slowest at mid-latitudes and the poles which travel at the same speed .
D) the same regardless of latitude.

Question 41

The element most abundant in the Sun is oxygen.

Question 42

Initially,scientists detected lower than the expected number of neutrinos from the sun.

Question 43

Most of the visible light from the sun originates in the photosphere.

Question 44

An older theory suggested that the corona was heated by shock waves from the convection zone.

Question 45

The energy emitted by the sun comes from chemical reactions.

Question 46

The Sun appears to rotate only because the Earth is revolving about the Sun.

Question 47

The corona is heated by the solar magnetic field.

Question 48

A filtergram is used to study layers below the photosphere.

Question 49

A giant fusion power reactor has been supplying all natural energy to the United States since 1776.

Question 50

The Zeeman Effect shows that sunspots contain magnetic fields.

Question 51

Sunspots are hotter than the photosphere.

Question 52

____________ of hydroden atom nuclei replace the heat the sun ____________ to keep it in equilibrium.

A) Nuclear fusion reactions; loses into space
B) Nuclear fusion reactions; gains from empty space
C) Chemical reactions; loses into space
D) Chemical reactions; gains from empty space
E) Nuclear fission; loses into space

Question 53

Solar prominences have twisted and looped shapes because of the solar magnetic field.

Question 54

Granulation is caused by rising currents of hot gas below the photosphere.

Question 55

A filtergram is used to study layers below the photosphere.

Question 56

The flash spectrum shows that temperature falls with increasing height in the chromosphere.

Question 57

Solar flares have no known effect on the Earth.

Question 58

Uranium serves as the source of the sun's energy because ...

A) uranium atoms can be fissioned into lighter atoms and energy
B) uranium atoms can be fused into helium and energy
C) uranium atoms can be fused into hydrogen and energy
D) none of the above because fusion of hydrogen atoms serves as the sun's source of energy
E) none of the above because fusion of helium atoms serves as the sun's source of energy

Question 59

There is only one form of neutrino.

Question 60

The sun has a continuous visual spectrum with dark absorption lines.The continuous spectrum is produced by the ____________ layer while the dark absorption lines are produced by ____________layers.

A) inner chromosphere,outer photosphere
B) inner photosphere,outer chromosphere
C) inner chromosphere,outer corona
D) inner corona,outer chromosphere

Question 61

The dynamo effect is believed to produce the ____________________ of the sun.

Question 62

The ____________________ of the sun is composed of ionized gas and produces a continuous spectrum with a superimposed emission spectrum.

Question 63

Most of the light we see coming from the sun originates in the ____________________.

Question 64

The ____________________ shows that sunspots are associated with magnetic activity.

Question 65

Most of the neutrinos from the sun originate in the core..

Question 66

Sunspots often appear in pairs.

Question 67

If energy is carried by the bulk motion of matter,that is called ____________________.

Question 68

The study of the oscillations of the surface and interior of the sun is known as ____________________.