WorksheetsAstro final - sun
Total questions: 25
Worksheet time: 13mins
Hydrostatic equilibrium is a balance between
heat and centrifugal force.
core temperature and surface temperature.
pressure and gravity.
radiation and heat.
Where does hydrostatic equilibrium exist in the Sun?
only in the core, where energy production via fusion can balance gravity
in the outer layers of the atmosphere, where most of the visible light is produced
just outside the core, where heat from nuclear fusion is transported outward
throughout the Sun
The balance of energy in the solar interior means that
energy production rate in the core equals the rate of radiation escaping the Sun’s surface.
the source of energy in the core is stable and will sustain the Sun for millions of years.
the outer layers of the Sun absorb and re-emit the radiation from the core at increasingly longer wavelengths.
radiation pressure balances the weight of the overlying solar layers.
The majority of the Sun’s energy comes from
gravitational contraction.
nuclear fission of uranium.
hydrogen fusion.
helium burning.
What is the approximate temperature at the center of the Sun?
106 K
1.5 ´ 107 K
2.5 ´ 107 K
10,000 K
The net result of the proton-proton chain of nuclear reactions is that four protons are converted into
four helium nuclei as well as energy and neutrinos.
one helium nucleus as well as deuterium, electrons, and energy.
one helium nucleus, as well as energy and neutrinos.
two helium nuclei, as well as neutrinos and energy
Suppose by some mysterious process that the nuclear fusion rate in the core of the Sun were to increase. What would happen to the appearance of the Sun?
It would shrink so that the higher gravity could balance the increased pressure from the core.
It would grow larger and hotter, making it more luminous.
It would grow larger but stay at the same temperature, making it more luminous.
It would grow larger but cooler.
If the core of the Sun were hotter than it is now, how would the Sun’s energy production change?
It would produce less energy per second than it does now.
It would produce more energy per second than it does now.
Its energy production would vary more than it does now.
Its energy production would be more stable than it is now.
The energy that fuels the Sun is generated
only on its surface.
only in its core.
only in the solar wind.
both in its core and on its surface.
In the radiative zone inside the Sun, photons are transported from the core to the convective zone over a time of
many thousands of years.
many millions of years.
seconds
a few hours.
Which of the following method(s) is (are) not used to transport energy from the core of the Sun to its surface?
radiation
convection
conduction
All of the above are important in the solar interior.
The interior zones of the Sun are distinguished by
jumps in density between zones.
their temperature profiles.
pressure differences inside each zone.
their modes of energy transport.
Which of the following layers of the Sun makes up the majority of its interior?
the core
the radiative zone
the convective zone
the photosphere
Approximately how long does it take the photons released in nuclear reactions in the core of the Sun to exit the Sun?
8 minutes
16 hours
1,000 years
100,000 years
Which of these can travel directly from the center of the Sun to Earth in about 8 minutes?
photons
electrons
protons
neutrinos
What makes neutrinos so different from other particles of matter?
They interact very weakly with other particles.
They interact very strongly with other particles.
They are the only particles that move quickly.
They move very slowly.
How was the solar neutrino problem solved?
by postulating that neutrinos have a very large mass
by postulating that neutrinos oscillate between three different types
by postulating that some neutrinos become photons during their journey
by postulating that some neutrinos interact more strongly with matter such that they are absorbed locally inside the Sun
The detection of solar neutrinos confirms that
the Sun’s core is powered by proton-proton fusion.
energy transport by radiation occurs throughout much of the solar interior.
magnetic fields are responsible for surface activity on the Sun.
convection churns the base of the solar atmosphere.
Why do sunspots appear dark in pictures of the Sun?
They are too cold to emit any visible light.
They actually are fairly bright but appear dark against the even brighter background of the surrounding Sun.
They are holes in the solar surface through which we can see to deeper, darker layers of the Sun.
They are tiny black holes, absorbing all light that hits them.
Which of the following statements about the sunspot cycle is FALSE?
The number of sunspots peaks approximately every 11 years.
With each subsequent peak in the number of sunspots, the magnetic polarity of the Sun is the reverse of the previous peak.
The rate of nuclear fusion in the Sun peaks about every 11 years.
The rate of nuclear fusion in the Sun peaks about every 11 years.
Which of the following statements about the violent events on the Sun called flares is FALSE?
flares happen more often during solar maximum, and sometimes during those periods, there can be several in one day
a flare can release energy equivalent to a million hydrogen bombs
flares originate in the upper part of the corona, in the regions called coronal holes
astronomers think that flares are connected with sudden changes in the magnetic field of the Sun
Astronomers now realize that active regions on the Sun are connected with
the dark regions between the bright granulation cells on the photosphere
loops of magnetic field emerging from the surface of the Sun
the absence of sunspots during a solar minimum
great tropical storm systems in the Earth's atmosphere
Solar wind particles can be captured by the Earth's magnetosphere. When these particles spiral down along the magnetic field into the atmosphere, they are responsible for:
aurorae (northern and southern lights)
tropical storms (regions of rapidly rotating air)
the greenhouse effect
the reddish color we see during sunsets
Which part of the Sun's atmosphere is the hottest?
chromosphere
transition region
corona
just above the photosphere
The Sun’s photosphere is
the central region where the energy of the Sun originates
the part of the Sun from which the light comes that we see when we look at the Sun with our eyes
the hottest region of the Sun
the outermost layers of the Sun’s atmosphere
