Deck 10: The Sun: Our Parent Star

Question 1

The final step in transporting energy to the surface of the Sun is via convection.

Answer 1

True

Question 2

The Sun's magnetic field is very weak compared to Earth's.

Answer 2

False

Question 3

The solar wind is constantly removing mass from the Sun.

Answer 3

True

Question 4

The solar constant refers to that fact that the Sun's luminosity has remained unchanged in the age of the solar system.

Question 5

The sunspot cycle averages about 11 months.

Question 6

The granules in the photosphere are about as big as Texas, or around 1,000 km across.

Question 7

Sunspots usually come in pairs of north and south magnetic poles.

Question 8

The thickness of the photosphere is about 100 times the diameter of the Earth, and large sunspots are larger than our whole planet.

Question 9

The photosphere is the coolest layer close to the Sun, for the radiation of visible light allows it to cool off efficiently.

Question 10

The Sun's radius is one astronomical unit by definition.

Question 11

The prolonged period of few sunspots between 1645 and 1715 is known at the Maunder Minimum.

Question 12

Observations of sunspots at different solar latitudes prove that the Sun, like the gas giants, rotates differentially.

Question 13

The Sun's average density is about the same at Jupiter's, suggesting a similar composition.

Question 14

The Sun's structure is uniform throughout its interior, with no evidence of different layers.

Question 15

The solar corona is much cooler than the Sun's surface; hence, we must wait for a total solar eclipse to glimpse it with the naked eye.

Question 16

The chromosphere is faint because of its low density.

Question 17

Granulation is the most obvious proof of solar convective energy transport.

Question 18

A typical solar flare lasts only a few days.

Question 19

The proton storms in the solar wind travel at almost the speed of light.

Question 20

The bright photosphere is much hotter than the faint corona.

Question 21

The proton- proton cycle converts all of the mass of the four hydrogen atoms into pure energy.

Question 22

The solar corona is best studied using X- ray telescopes.

Question 23

Although sunspots are cooler areas in the photosphere, when they increase in number that tells us the Sun is becoming more active.

Question 24

The temperature of the photosphere is about

A) 3,200 K.
B) 5,800 K.
C) 11,000 K.
D) one million K.
E) ten million K.

Question 25

Unlike the nuclear reactions in the Sun, everyday chemical reactions involve only the electromagnetic forces.

Question 26

The current sunspot cycle is the most active in a century.

Question 27

The solar neutrinos observed on Earth come from the hot spots in the corona.

Question 28

Without the strong nuclear force, the universe would be made only of hydrogen.

Question 29

In the proton- proton chain, helium atoms are fused into hydrogen.

Question 30

Given that a large sunspot, about 100× smaller than the Sun, is about the same size as our planet, how many Earths could fit inside the Sun's vast volume?

A) 100
B) 1,000
C) 10,000
D) 100,000
E) one million

Question 31

The Sun produces energy by fusing hydrogen into helium.

Question 32

The Sun is actually more luminous at sunspot minimum than at maximum.

Question 33

Most of the neutrinos given off by the Sun are changing form in the eight minutes before they reach us.

Question 34

During the fusion process, mass is converted into energy.

Question 35

Although protons repel each other at a distance, they will actually bind if they come close enough together.

Question 36

The Solar Neutrino Problem is that we observe more neutrinos than predicted.

Question 37

Prominences are extensions of the solar magnetic fields above sunspots.

Question 38

Solar neutrinos take a little more than eight hours to get from the Sun's core to Earth.

Question 39

The average density of the Sun is most similar to which object?

A) the Earth
B) the Moon
C) Halley's Comet's nucleus
D) Mercury
E) Jupiter

Question 40

What is the meaning of the solar constant?

A) the fact that the amount of hydrogen turning into helium in the core is fixed
B) the stability of the Sun's luminosity for as long as life has existed on Earth
C) the regularity of the 11- year sunspot cycle
D) the amount of energy the Earth receives per unit area and unit time
E) the fact that features on the Sun appear to never change

Question 41

How long does the sunspot cycle last, on average?

A) 365.25 days
B) about 11 years
C) about seven years
D) about 76 years
E) between 25 and 35 days

Question 42

Which of these are NOT associated with the active Sun?

A) flares
B) aurora
C) sunspots
D) granulation
E) prominences

Question 43

A maximum in solar activity should next occur about

A) 2020.
B) 2017.
C) 2019.
D) 2023.
E) 2027.

Question 44

From inside out, which is in the correct order for the structure of the Sun?

A) core, photosphere, radiative zone, corona
B) core, chromosphere, photosphere
C) core, convective zone, radiative zone
D) core, convective zone, radiative zone, granulation
E) core, radiative zone, convective zone, chromosphere

Question 45

While observing the Sun, you note a large number of sunspots. What can you conclude?

A) Earth's climate will be unusually cold.
B) There are likely to be an above average number of flares and prominences.
C) The Sun is less luminous than usual.
D) The Sun's rotation is slower than average.
E) This is a period of low solar activity.

Question 46

The critical temperature to initiate the proton- proton cycle in the cores of stars is

A) 3,000 K.
B) 5,800 K.
C) 2,300,000 K.
D) 10 million K.
E) 100 million K.

Question 47

What natural barrier usually prevents two protons from combining?

A) gravity
B) electromagnetic repulsion
C) the strong nuclear force
D) dark energy
E) the weak nuclear force

Question 48

Sunspots

A) were most numerous during the Maunder Minimum.
B) come in pairs, representing the north and south magnetic fields.
C) are always found close to the Sun's poles.
D) are relatively constant in number every year.
E) travel over the surface of the Sun from pole to pole.

Question 49

What two energy transport mechanisms, in order from outside the core to the surface, are found in the Sun?

A) conduction; radiation
B) conduction; convection
C) radiation; convection
D) radiation; conduction
E) convection; conduction

Question 50

The outward pressure of hot gas in the Sun

A) weakens the magnetic field.
B) is responsible for variations in the sunspot cycle.
C) is increasing the Sun's diameter.
D) is cooling the photosphere.
E) is balanced by the inward gravitational pressure.

Question 51

As the Sun rotates, an individual sunspot can be tracked across its face. From eastern to western limb, this takes about

A) 12 hours.
B) two weeks.
C) a week.
D) 5.5 years.
E) a month.

Question 52

Visible sunspots lie in the

A) granulation in the photosphere.
B) corona.
C) chromosphere.
D) radiative zone.
E) transition zone.

Question 53

During a period of high solar activity, the corona

A) disappears.
B) is more irregular.
C) shrinks to half its normal size.
D) becomes smooth and even.
E) cools almost to the temperature of the photosphere.

Question 54

The most striking example of solar variability was the

A) Maunder Minimum from 1645- 1715.
B) Joseph's seven lean years in the Old Testament.
C) Sporer Minimum that doomed the Anasazi.
D) the fall of Rome.
E) Dust Bowl drought of the 1930s.

Question 55

When we glimpse the chromosphere at the start and end of totality, its color is

A) white from the moonlight.
B) green (the famous flash).
C) blue, due to the ionization of nitrogen by the magnetic fields.
D) yellow, like the photosphere below it.
E) red, due to ionized hydrogen at lower pressure.

Question 56

A loop of gas following the magnetic field lines between sunspots' poles is a

A) coronal hole.
B) prominence.
C) ray.
D) flare.
E) coronal mass ejection.

Question 57

The solar winds blow outward from

A) coronal holes.
B) sunspots.
C) the Sun's poles only.
D) flares.
E) the entire photosphere.

Question 58

Typically a granule in the photosphere is about

A) the size of Earth, around 12,000 km across.
B) the size of Texas, about 1,000 km across.
C) as big as Jupiter, around 100,000 km wide.
D) the size of our Moon, about 3,000 km across.
E) the size of a city, 20- 30 kilometers across.

Question 59

Sunspots are dark splotches on the Sun. Which statement is true?

A) They are extremely cold objects, as cold as Pluto.
B) They are hotter than the surrounding areas of the Sun.
C) They are associated with areas of very low magnetic fields.
D) They are extremely hot, but cooler than the surrounding areas of the Sun.
E) They are solid bodies floating on the surface of the Sun.

Question 60

Suppose a large flare is detected optically. How long until radio interference arrives?

A) simultaneously
B) 8.5 minutes later
C) about 12 hours
D) about four days
E) no relation between the two

Question 61

The corona can only be glimpsed from Earth during a(n) .

Question 62

A loop or sheet of gas hanging above an active region of the Sun is a(n) , often striking along the limb during total eclipses.

A) aurora
B) granule
C) sunspot
D) prominence
E) flare

Question 63

A solar _ is a sudden, violent disruption around sunspots, releasing a tremendous amount of energy in almost all wavelengths.

A) prominence
B) aurora
C) granule
D) flare
E) sunspot

Question 64

Which is the net result of the proton- proton chain?

A) 2 protons -deuterium + a positron + an antineutrino + X- rays
B) 4 protons -1 helium 4 + a positron + a neutrino + gamma rays
C) 4 protons -1 helium 4 + 2 neutrinos + gamma rays
D) 4 protons -2 helium 2 + 2 positrons + ultraviolet radiation
E) 6 protons -2 helium 4 + 3 positrons + 3 neutrinos + gamma rays

Question 65

The transport subsurface material from the Sun's equator to its poles and back at a depth far below the convection zone.

Question 66

Compared to the underlying photosphere and chromosphere, the corona is in temperature.

Question 67

The high temperature of the corona is directly responsible for

A) prominences.
B) the solar wind.
C) flares.
D) sunspots.
E) aurora.

Question 68

The strongest magnetic fields in the photosphere lie near

A) granules.
B) auroras.
C) prominences.
D) flares.
E) sunspots.

Question 69

The pattern of hot convective cells rising in the photosphere is called

A) aurora.
B) granulation.
C) sunspots.
D) flares.
E) prominences.

Question 70

The _ - year solar cycle is characterized by a variation in the number of sunspots through a reversal of the magnetic polarity of the Sun as a whole.

A) 2
B) 10
C) 11
D) 22
E) 44

Question 71

Stellar spectra tell us that is the second most abundant element in the Sun.

A) iron
B) helium
C) oxygen
D) carbon
E) hydrogen

Question 72

While the photosphere produces chiefly visible light, most coronal energy is in the form of

A) radio waves.
B) infrared radiation.
C) ultraviolet light.
D) gamma rays.
E) X- rays.

Question 73

In the proton- proton cycle, the helium atom and neutrino have less mass than the original hydrogen. What happens to the "lost" mass?

A) It is transformed into electrons.
B) It is recycled back into hydrogen.
C) It is converted to energy.
D) It is ejected into space.
E) Conservation of mass dictates no mass can be lost.

Question 74

The speed of light is 3.00 × 108 m/s. If 2.00 kg of mass is converted to energy, how much energy will be produced?

A) 6.00 × 108 J
B) 1.80 × 1017 J
C) 9.00 × 1016 J
D) 1.50 × 108 J
E) 6.00 × 104 J

Question 75

The blows out of the coronal holes.

Question 76

The two spacecraft constantly observing the Sun are _ _ and .

Question 77

The primary source of the Sun's energy is

A) gravitational collapse of the helium towards the core.
B) dark energy.
C) the weak force creating energy from uranium decay.
D) the strong force fusing hydrogen into helium.
E) oxidation of carbon in the core.

Question 78

The solution to the solar neutrino problem was

A) the Sun's core is cooling down, producing less neutrinos that expected.
B) 2/3 of the neutrinos transform into a new type during the 8- minute trip to Earth.
C) the Earth's ozone layer absorbs 2/3 of the neutrinos in transit.
D) the corona is opaque to much of the neutrino radiation.
E) our solar energy equations were just wrong, and needed much reworking.

Question 79

Sunspots are _ poles in the photosphere.

Question 80

In the proton- proton cycle, the positron is

A) a spin conservation particle.
B) the chief means energy reaches the photosphere.
C) intermediate between the proton and neutron in mass.
D) massless.
E) an anti- electron.