Multiple-Choice Questions

1) 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.

Page Ref: 9.1

2) 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

Page Ref: 9.1

3) What is the meaning of the solar constant?

A) the regularity of the 11 year sunspot cycle

B) the fact that features on the Sun appear to never change

C) the stability of the Sun's luminosity for as long as life has existed on Earth

D) the amount of energy the earth receives per unit area and unit time

E) the fact that the amount of hydrogen turning into helium in the core is fixed

Page Ref: 9.1

4) The Sun's average density is almost exactly the same as

A) Halley's Comet.

B) Jupiter.

C) the earth.

D) Saturn.

E) our Moon.

Page Ref: 9.2

5) Which of these are not associated with the active Sun?

A) sunspots

B) prominences

C) granulation

D) flares

E) aurora

Page Ref: 9.2

6) Typically a granule in the photosphere is about

A) the size of a city, 20-30 kilometers across.

B) the size of Texas, about 1,000 km across.

C) the size of our Moon, about 3,000 km across.

D) the size of Earth, around 12,000 km across.

E) as big as Jupiter, around 100,000 km wide.

Page Ref: 9.2

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

A) convection, conduction.

B) radiative diffusion, convection

C) conduction, radiative diffusion

D) radiative diffusion, conduction

E) conduction, convection

Page Ref: 9.2

8) The outward pressure of hot gas in the Sun

A) is balanced by the inward gravitational pressure.

B) is increasing the Sun's diameter.

C) is cooling the photosphere.

D) is responsible for variations in the sunspot cycle.

E) weakens the magnetic field.

Page Ref: 9.2

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

A) green (the famous flash).

B) yellow, like the photosphere below it.

C) red, due to ionized hydrogen at lower pressure.

D) blue, due to the ionization of nitrogen by the magnetic fields.

E) white from the moonlight.

Page Ref: 9.3

10) The solar winds blow outward from

A) sunspots.

B) flares.

C) the entire photosphere.

D) coronal holes.

E) the Sun's poles only.

Page Ref: 9.3

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

A) core, convective zone, radiative zone

B) photosphere, radiative zone, corona

C) radiative zone, convective zone, chromosphere

D) core, chromosphere, photosphere

E) convective zone, radiative zone, granulation

Page Ref: 9.3

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

A) a flare.

B) a ray.

C) a coronal hole.

D) a prominence.

E) a coronal mass ejection.

Page Ref: 9.4

13) How long does the sunspot cycle last, on average?

A) between 25 and 35 days

B) 365.25 days

C) about seven years

D) about 11 years

E) about 76 years

Page Ref: 9.4

14) Visible sunspots lie in the

A) chromosphere.

B) transition zone.

C) corona.

D) radiative zone.

E) granulation in the photosphere.

Page Ref: 9.4

15) 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) a week.

C) two weeks.

D) a month.

E) 5.5 years.

Page Ref: 9.4

16) The most striking example of solar variability was the

A) Dust Bowl drought of the 1930s.

B) Maunder Minimum from 1645-1715.

C) Sporer Minimum that doomed the Anasazi.

D) the fall of Rome.

E) Joseph's seven lean years in the Old Testament.

Page Ref: 9.4

17) A maximum in solar activity should next occur about

A) 2004.

B) 2008.

C) 2012.

D) 2015.

E) 2017.

Page Ref: 9.4

18) Sunspots

A) are always found close to the Sun's poles.

B) come in pairs, representing the north and south magnetic fields.

C) were most numerous during the Maunder Minimum.

D) travel over the surface of the Sun from pole to pole.

E) are relatively constant in number every year.

Page Ref: 9.4

19) During a period of high solar activity, the corona

A) disappears.

B) is more irregular.

C) cools almost to the temperature of the photosphere.

D) becomes smooth and even.

E) shrinks to half its normal size.

Page Ref: 9.4

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

A) They are hotter than the surrounding areas of the Sun.

B) They are extremely cold objects, as cold as Pluto.

C) They are extremely hot, but cooler than the surrounding areas of the Sun.

D) They are solid bodies floating on the surface of the Sun.

E) They are associated with areas of very low magnetic fields.

Page Ref: 9.4

21) 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

Page Ref: 9.4

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

A) The Sun is less luminous than usual.

B) This is a period of low solar activity.

C) Earth's climate will be unusually cold.

D) The Sun's rotation is slower than average.

E) There are likely to be an above average number of flares and prominences.

Page Ref: 9.4

23) What natural barrier must be overcome for two protons to collide and fuse together?

A) dark energy

B) gravity

C) electromagnetic repulsion

D) the strong nuclear force

E) the weak nuclear force

Page Ref: 9.5

24) The critical temperature the core must reach for a star to shine by fusion is

A) 5,800 K.

B) 11,000 K.

C) 127,000 K.

D) 10 million K.

E) 100 million K.

Page Ref: 9.5

25) 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 recycled back into hydrogen.

B) It is ejected into space.

C) It is converted to energy.

D) It is transformed into electrons.

E) Conservation of mass dictates no mass can be lost.

Page Ref: 9.5

26) The solution to the solar neutrino problem which won a Nobel Prize in 2002 was

A) the Sun's core is cooling down, producing less neutrinos that expected.

B) the corona is opaque to much of the neutrino radiation.

C) the earth's ozone layer absorbs 2/3 of the neutrinos in transit.

D) 2/3 of the neutrinos decay into a new form in the 8 minutes to Earth.

E) our solar energy equations were just wrong, and needed much reworking.

Page Ref: 9.5

27) Today, the primary source of the Sun's energy is

A) oxidation of carbon in the core.

B) gravitational collapse of the helium coreward.

C) dark energy.

D) the strong force fusing hydrogen into helium.

E) the weak force creating energy from uranium decay.

Page Ref: 9.5

28) In the proton-proton cycle, the positron is

A) massless.

B) a spin conservation particle.

C) an anti-electron.

D) the chief means energy reaches the photosphere.

E) intermediate between the proton and neutron in mass.

Page Ref: 9.5

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

A) 4 protons = 1 helium 4 + a positron + a neutrino + gamma rays

B) 2 protons = deuterium + a positron + an antineutrino + x-rays

C) 4 protons = 2 helium 2 + 2 positrons + ultraviolet radiation

D) 4 protons = 1 helium 4  + 2 neutrinos + gamma rays

E) 6 protons = 2 heliums + 3 positrons + 3 neutrinos + gamma rays

Page Ref: 9.5

30) 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) 1.80 × 1017 J

B) 6.00 × 108 J

C) 1.50 × 108 J

D) 6.00 × 104 J

E) 9.00 × 1016 J

Page Ref: 9.5